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A study of the biological changes taking place in the heterogenous microbial population of an anaerobic digester during the period of adaptation to a synthetic substrate and the procedure used to adapt the population to the new substrate is described. Adaptation from raw sewage sludge to the new substrate was followed by chemical, enzymic and bacteriological analyses of the liquid and the solid phases in the digester. Results indicate that although the chemical composition of the effluent did not show any significant changes over the period of adaptation, the chemical, enzymic and bacteriological properties of the sludge phase changed markedly. Results also indicate that adaptation to the new substrate was not complete after 60 days operation since the microbial population was still changing as indicated by intermediate enzyme activities and the number of micro-organisms present per unit volume.

The Nash method for formaldehyde, based on formation of a yellow product when formaldehyde reacts with acetylacetone and an ammonium salt, was applied to maple sirup. A procedure was developed for separating the formaldehyde from the sirup. A constant blank value of 0.9 ppm of formaldehyde was established. Best results are obtained with sirups containing less than 6 ppm of formaldehyde. Collaborative study is planned.

An adaptation of a moist-chamber method is described whereby Verticillium albo-atrum, V. dahliae, and V. nigrescens can readily be isolated from herbaceous and woody hosts and easily identified. Segments of infected stems, petioles, and roots cut transversely can be observed microscopically at daily or frequent intervals to determine the origin of outgrowing fungal hyphae in the absence of troublesome contaminants.

In recent papers by the author the fact has been pointed out that certain species of the Erysiphaceœ are able, under cultural conditions, to infect their host-plants vigorously when their conidia or ascospores are sown on the cells of the internal tissues exposed by means of a wound, although the fungi in question are confined normally to the external surface of the epidermal cells. The present paper gives the results of investigations carried out in the laboratory of Professor Marshall Ward at Cambridge, with the object of ascertaining the details of growth of the fungus under these abnormal conditions, and of discovering to what extent the hyphæ penetrated into the intercellular spaces of the internal tissues, and whether haustoria (normal or otherwise) were produced by these hyphæ.

The preceding paper of this series considered a group of Phytolacca populations in tropical America, where active hybridization between quite divergent species has produced extraordinary morphological variability. *The present paper considers a more subtle kind of variation found within the single species P. americana L. (= P. decandra L.), commonly called poke. This species, a native of the eastern United States, is almost completely' isolated from other members of its genus; it shows no traces of hybridization except in some Gulf Coast colonies which are to be discussed in the succeeding paper of this series. Poke is strikingly uniform morphologically throughout most of its range. Comparisons of herbarium specimens, even if drawn from widely separated areas, ordinarily show only the kind of slight quantitative differences which might be attributed simply to varying environmental conditions. -Such flat homogeneity 'is remarkable in view of the wide range of the species, which extends from the Atlantic Coast to the Great Plains and from southeastern Canada to the Rio Grande valley and the Gulf of Mexico. Considering the north-south extent alone, it is apparent that the species must contend with very diverse climatic situations. Its range through more than 200 of latitude includes strongly contrasting day lengths and light intensities. Moreover, though poke has hardy perennial roots, its shoots are extremely sensitive to frost. The northernmost colonies must complete growth and seed production within a frost-free period of less than five months, while the southernmost colonies, living in a zone where years may pass without frost, continue to bloom and fruit through the entire year. Adaptation of a single species, to such diverse environments might be expected to involve evolution of genetically different strains. To explore the possibility that some of the subtle morphological variations in poke are genetically fixed, rather than the direct result of environmental effects, an experimental planting was made in which poke plants derived from different latitudes were grown together under uniform conditions.

does not appear. First page follows. Introduction The selection and breeding of plants resistant to parasites had its inception chiefly in the field of plant pathology, more specifically in the development of cereals resistant to rust. While the breeding for resistance to insects is still in its infancy, the possibilities in this field appear to be almost unlimited. In certain cases, among which may be mentioned the control of onion thrips, breeding for resistance seems to offer promise. In this paper are presented data which show that in the case of the onion certain varieties do possess a definite resistance to thrips, and the characters thought to be responsible for this resistance are described in some detail. Howitt,(22)5 McColloch,(30) Martin,(29) and others have given excellent general reviews of the development of resistant crop plants; here only the more important papers concerned with resistance to sucking insects are reviewed. The causes of resistance to insects have been grouped by Wardle and Buckle,(43) McColloch,(30) and Wardle(42) as physical, chemical, or physiological. The first category includes such characters as hairiness, thickness of epidermis, thickness of seed coat and rind, and habit of growth; the second, the presence of such compounds as acids, alkaloids, essential oils, and tannin together with the potash-phosphoric acid ratio; the third, such characters as vigor, seasonal adaptation, early maturity, ability to recover from injury, aand po-sitive or negative response to specific stimuli. In most instances, however, the characters, whether physical (morphological), chemical, or physiological, are probably genetic in nature and are therefore governed by the laws of inheritance. Resistance may result from one character, or from several combined; and the effectiveness of a character may vary with the soil condition and climate. Among the physical or morphological characters that seem to be intimately associated with host resistance is hairiness.

The factors which influence response and adjustment in the physiology of insects are too numerous to discuss them all in the time available. It seems better, therefore, to limit this paper to a discussion of one or two factors and to deal with them more fully. One of these, which appears to have a marked effect upon the way an insect will react to external stimuli, is a comparatively new study in insect physiology. It is the presence of countless minute particles called colloids in all of the cells of the body and in the liquids which bathe the cells. So profound and far-reaching appears to be the effect of the activity of these particles and so little has the subject been studied in entomology or even in biology that the writer will limit his paper to this phase of response and adjustment, and will describe some experiments recently conducted in which collo dal activity was found to play an important part.

Many of the subjects in this paper will be con? sidered in greater detail in a more complete review of anuran metamorphosis now in preparation in collaboration with Thomas Peter Bennett, Rockefeller Institute, N. Y. This longer review, which approaches anuran metamorphosis from a more comparative viewpoint, will appear in vol. V of Comprehensive Treatise on Comparative Biochem? istry, edited by M. Florkin and H. Mason, Aca? demic Press, New York, 1961. I am therefore greatly indebted to T. P. Bennett for his many valuable contributions to this paper. The major part of the experimental work from the author's laboratory and the preparation of this manuscript was aided by grant C-3006 from the United States Public Health Service. I am pleased to acknowledge my appreciation to Dr. Jane Kaltenbach for many helpful discus? sions and to Carla Ferguson for her valuable as? sistance in the preparation of this manuscript. E. Alterations of serum proteins of X. laevis. 129 F. Total serum protein concentra? tion. 129

does not appear. First page follows. Introduction The genus Protodiaspis is probably native to the Western Hemisphere, where it occurs almost exclusively on oaks. The genus includes a somewhat larger number of species than the average diaspidid genus of North America. (Ferris (1937))4 questioned the homogeneity of Protodiaspis but did not attempt to subdivide it. The genus is of special interest because the females are incompletely pupillarial; the molt of the second instar does not quite cover the adult female, which may also possess a rudimentary or woolly scale. The morphological diversity within the genus seems, however, to be simply due to increasing adaptation to the pupillarial type of existence (Brown and McKenzie, 1962), the second paper in this issue). In addition to the evolutionary trends within the genus itself, forms similar to it may have been ancestral either to completely pupillarial types, or to forms with little or no covering; these possibilities have been further considered in relation to the chromosomal systems of the Diaspididae by Brown and McKenzie in the paper just cited. Many of the species of Protodiaspis are native to Mexico, where the oak forests are being destroyed to open land for cultivation. In view of the central position which Protodiaspis holds in current concepts of the evolution of the armored scales, it is to be hoped that entomologists will continue to collect it whenever possible. Descriptions of Two New Species One new species of Protodiaspis is described from Guatemala and the other from Arizona. Both show close relationship to other components of the genus, and thus provide further examples of evolutionary change in the group. Determination of the chromosome system and numbers in the first-described species not only aids in its proper identification, but also contributes to our understanding of the evolutionary sequence of these Coccoidea.

Sub-units of a species living in contrasting environments may respond to differences in their respective habitats by developing differentially adaptive traits. For example, Moore (1942, 1946, and 1949) has demonstrated differences in both developmental temperature tolerances and coefficients between northern and southern populations of R. pipiens. Also, Ruibal (1955) has shown that populations of R. pipiens from different elevations in Mexico exhibit different rates of development at all temperatures tested. Embryos from higher elevations develop more slowly than their lowland counterparts. Ruibal suggests that this difference may be due to a history of selection for rapid development in the lowland localities resulting from greater interspecific competition in the larval stage. This phenomenon, called special adaptation by Brown (1958), may be most conveniently elucidated by comparing different conspecific local populations which are geographically proximate, thus minimizing the effects of differentiation due to isolation by distance. An opportunity to study this mechanism under near optimal conditions is afforded by populations of the boreal chorus frog, Pseudacris triseriata (Weid), in northern Colorado. In this area populations of P. triseriata occur at elevations from less than 4900 ft to above 10,000 ft. A presumed result of this elevation gradient has been the development and maintenance of numerous differences between montane and and piedmont chorus frogs. Variations in body size, adult temperature tolerance, and metabolism have been described in a previous paper (Pettus and Spencer, 1964). The purpose of this paper is to report our observations on variations in the eggs of these frogs and the results of a series of experiments designed to reveal differences in temperature effects during development. Both Moore (1949) and Ruibal (1955) have reported geographic variation in egg size of Rana pipiens. Moore's data show, with one striking reversal, a correlation between increased egg diameter and increased latitude. Ruibal reported only minor variation in egg diameters in spite of the fact that his samples were drawn from populations over a wide range of elevations.

The importance of species differences in drug metabolism in understand­ ing the mechanism of action of many drugs has become increasingly evi­ dent. Several reviews and articles on the overall topic of drug metabolism have covered aspects of it (1-17). In addition, discussion of species differ­ ences in drug metabolism formed an important segment of a recent sympo­ sium, the proceedings of which contain a number of very informative papers (18-24). It would appear that the increasing interest in the subject stems from the premise that improved understanding and broader knowledge of species differences in drug metabolism will greatly improve our abilities to predict the pharmacologic and toxic010gic properties of a given compound in man from experimental data obtained in animals. It should also be pointed out that such studies, even when only indirectly reIated to drug therapy, have yielded valuable new biochemical information of quite fundamental nature. Examples of this type concern acetyl CoA, the role of pyridine nucleotides in oxygen incorporation, mechanisms of enzyme adaptation, human genetics, phylogenetic and ontogenetic enzyme development, intracellular structure, organ and membrane function, and biosynthesis of vitamin C (25). The in­ creased interest is also probably correlated with recent technological adv­ ances that will possibly enable one to study the physiological disposition and metabolic fate of a compound in several species within a relatively short pe­ riod of time. If the above comments sound encouraging, they may also be unduly opti­ mistic, at least insofar as prediction is concerned. For example, Williams (19) stated that aromatic hydroxylation varies quantitatively and qualita­ tively in haphazard fashion among species, and that one can not, at present, draw definite conclusions about the relationship between drugs, species, and metabolic routes. Brodie (23) is equally discouraging in another sense, namely, the possibility of discovering an animal species, that, drug-metabo­ lism-wise, is greatly similar to man. It should be pointed out here, however, that very little work of this type has been done with the higher nonhuman primates, i.e., the chimpanzee, gorilla, and orang-utan. The reader should also beware of the catchall name "monkey"since in many papers it refers to

Introduction Climatic factors often strongly influence insect distributional patterns. Not only present but some past climatic influence may be reflected in existing distributional patterns, particularly if the insect is sedentary and limited in its ability to disperse. If the evolutionary history of sedentary groups of insects can be deduced and correlated with past habitats, it may provide valuable evidence concerning the sequence of past climates. This paper attempts to make such deductions, using as a basis the speciation and distributional patterns of certain genera of scarabaeid beetles. Much of our information on Pleistocene climates and past barriers to dispersal has been based on pollen studies (Dillon, 1956; Heusser, 1960; Wendorf, 1961) and on distributional patterns of vertebrates (Darlington, 1957). A number of papers on the subject have appeared in recent years, several of them obviously in disagreement. Comprehensive reviews on some aspects discussed here have been published by Deevey (1949), Dillon (1956), Dorf (1959), Flint (1957), Hubbs (19.58), Durham and Allison (1960), Martin and Harrell (1957), and Martin (1958). These papers give summaries of a number of aspects of Pleistocene climates and barriers that I mention briefly or omit entirely. Initially, there are two assumptions that have to be made concerning the antiquity of the genera under consideration, particularly as there is no fossil evidence. In the seven genera of Scarabaeidae considered, which are Mycotrupes, Peltotrupes, Gronocarus, Fossocarus, Acoma, Podolasia, and Pleocoma, all species are seemingly flightless, or at least the females are flightless, with the possible exception of Peltotrupes. Flightlessness itself is no indication of antiquity and may often be a recent adaptation since many large genera have some flightless species. However, when all the species in a genus are flightless, I believe it fair to assume that, in most cases, the flightless condition' developed early in their evolution. My first and most important assumption is that I am dealing with enough genera and species so that rapid evolutionary change in all of them seems unlikely, and therefore at least some of the species have a long evolutionary history. Supporting this important argument for antiquity is the fact that none of the genera considered appears to have closely related genera living today, at least in the New World. The early development of flightlessness on the generic level is also important to my second assumption: that flightless groups of allopatric species, existing in similar, restricted habitats and separated by seemingly minor barriers, are indicative of relict populations that have survived and evolved in the same general areas in which they occur today.

Gene flow has generally been regarded as detrimental to a population, its principal effect being to swamp a local population and prevent its adaptation to local conditions. The swamping effect has been considered so strong that prior isolation was thought to be a necessary first step in speciation. More recently it has been recognized that strong selection can produce divergence even in the face of a high rate of migration (Thoday and Gibson, 1962; Streams and Pimentel, 1961), while the experiments of Koopman (1950) show that sexual isolation can arise in populations in contact. This has raised the opposite question: why do we not have local speciation on a much greater scale, why are there any widespread species at all, why is not each local ecotype a distinct species? The obvious first answer refers to population size. As the environment becomes infinitely subdivided, local population size decreases, and the probability of random extinction increases. Suppose that the average number of offspring per pair is r, and each has a probability 1/r of survival. Then the probability that a population of size 2n becomes extinct by chance is [ 1 (1/r) ] rn which approaches el-n for large r. However, this probability decreases rapidly with n, and would not be an important factor for populations greater than several hundred. A second disadvantage to small population size is the loss of genetic variance through random drift, which might be important in very small populations, but the same objection applies as in the previous argument. Drift cannot account for the paucity of abundant but local species. It will be argued below that gene flow among populations is part of the adaptive system of a species, that there are optimum values for gene flow that depend on the statistical structure of the environment, and that natural selection can establish these optimal levels (or more precisely, that the actual levels of gene flow among populations of different species differ in the same direction as their optimal values). The model used here is a continuation of that used in the previous papers of this series (Levins, 1962, 1963, 1964). It is assumed that corresponding to each environment there is an optimum phenotype S, which may vary in time and space; that when the actual phenotype is the optimum, the adaptive value is maximized; and that fitness declines toward zero as the deviation of actual from optimum phenotype increases. (The phenotype is genetically determined. Any developmental or physiological modification of phenotype by the environment has the effect of reducing the environmental variance, as explained in the second paper of this series.) We further specialize the model by assuming that the fitness of each phenotype declines with the square of the deviation of that phenotype from the optimum, so that

Biochemical processes, set in motion by various stimuli and regulated by neural and humoral mechanisms, can be regarded as adaptive metabolic behaviour. Adaptation, as an adjustment to life challenges, however, does not assume a constant pattern of metabolic responses as being the most advantageous to the organism. The individual's interpretive reaction to environmental stimuli reflects genetic and environmental influences which have consequences in a complex varying pattern of biochemical responses. This study documents how two groups of individuals, collegiate oarsmen athletes and medical students, responded to environmental challenges with differing adaptive biochemical behaviours. Two separate but related experiments are reported in this paper. The first is the more comprehensive of the two and utilized collegiate oarsmen, while the second had first year medical students as subjects. In each case, the group was faced with what was considered to be a naturally stressful experience—in the case of the former, an intercollegiate collegiate rowing race,‡ and in the case of the latter, a final examination in a difficult subject.

Most lakes display extensive seasonal variation in both their biotic and abiotic components. The question posed in this paper is how do rotifers adapt to this temporal heterogeneity?. Three alternate models of population structure for temporal adaptation are advanced and considered. If the physiological state of population varies continuously with its environment, the relative fitness of a population will be constant. To test this hypothesis, rotifers (Euchlanis dilatata) were periodically collected from a nature, cloned, allowed to adapt to the laboratory environment for 10 generations, and then used in experiments to determine the intrinsic rate of population growth, r. The r values of clones collected at different times indicated that physiological adaptation alone is not the major factor involved in adaptation to seasonal variation. Moreover, the pattern of variation in r revealed genetic differences among clones collected at different times. An alternate explanation, genetic discontinuity through tim...

Among the great variety of biological rhythms with frequencies from less than 1/msec up to 1/several years,there are four rhythms which represent adaptations to time structures of the environment. These are the tidal, the diurnal, the lunar, and the seasonal rhythms. Using the diurnal or "circadian" rhythm as the most extensively studied example, the paper describes: (a) the properties of biological, self-sustained oscillators under constant conditions as well as under the influence of a synchronizing environmental rhythm; (b) the multiplicity of rhythmic functions in an organism, especially those of sensitivity to external stimuli, and (c) cases of internal desynchronization in man. After a brief outlook to rhythms with lower frequencies (weekly and seasonal rhythms), the final discussion deals with the problem of defining environmental hazards with regard to temporal organization in the environment as well as in the organism.

Although the embryologist has long ago given up the hope of being able to solve the phylogeny of any group of animals by his own labours alone, it is nevertheless just as true to-day as it was in the times he was buoyed up by that hope, that the data of Embryology, properly interpreted can and do furnish striking and demonstrative evidences of genetic relationships. That thesis constitutes the main theme of my discourse, and in the course of it I hope to show you how, starting from the relatively simple and generalised developmental conditions met with in the Lemuroidea, the much more specialized and secondarily modified relations found in the higher Primates may be supposed to have arisen as the result of continued adaptive modification, involving more especially acceleration and abbreviation in the developmental processes. The germ of the higher mammal, developing as it does in the uterus of the mother, has its old ancestral tendencies modified as the result of adaptation to its maternal environment and before it can proceed in earnest to carry out its primary function of forming an embryo, its most pressing necessity, since it has little or no food-reserves stored up in itself, is to make the earliest possible provision for its own nutrition. Consequently we find in the different Orders of Mammals the most varied structural adaptations designed to this end and affecting particularly the foetal membranes and their relations to the uterus. But no Order, I venture to think, can compare with the Primates in the wealth of material it provides for the study of such developmental adaptations.

Although the effect of temperature on the rate of embryonic growth in Amphibia was known before the turn of the last century, it remained for Lillie and Knowlton ('97) to supply the first quantitative data on the subject. They found that as the temperature was increased above the lowest at which eggs of Amnbystoma tigriium or Rana pipiens can develop, the time necessary to reach a given morphological stage becomes progressively less, until a temperature is reached above which normal development does not occur. It was also recognized that the time-temperature curve resembles those "measuring the rapidity of known chemical processes at different temperatures." In view of the work to be presented, it is of interest that they found the temperature tolerance of eggs to be correlated with environmental conditions. The eggs of species breeding early in the year when the water was cold, could tolerate a lower temperature than could those of forms breeding later in the spring. This paper of Lillie and Knowlton was followed by the masterly investigations of Hertwig in 1898, and others such as those of Galloway ('00), King ('03), Chambers ('08), Krogh ('14), Dempster ('33), Atlas ('35), and Knight ('38). The present investigations are concerned with a comparison of the effects of temperature on the embryos of different amphibians. The temperature tolerance and rates of development, over a wide range of temperatures have been determined in four species of frogs. A comparison of developmental rate among four species of salamanders and between two toads has been made. Correlations between temperature tolerance and rates of development on one hand, and breeding habits and geographic distribution on the other, have led to certain conclusions regarding adaptation to environmental temperature

Even the most casual observer has noticed that the various species of amphibians do not frequent the same type of surrouindings. A student of ecology finds that practically every species of amphibian has a distinctive habitat, and that the habitats range from strictly aquatic to almost totally terrestrial. In the transition from the aquatic to the terrestrial mode of life among amphibians, the problem of the conservation of body moisture presents itself. To an aquatic species which is constantly bathed in water, this offers no difficulty. But a terrestrial species is obviously exposed to the effects of evaporation for long periods of time, and therefore must replace the surface moisture lost through evaporation from its reserve within the body. In order to endure a comparatively dry habitat and to cope with the inevitable loss of body water, a terrestrial amphibian evidently must possess some adaptation not present in an aquatic form, or present in a smaller degree. To explore this problem, a series of experiments were performed, in which, under controlled conditions, specimens of several species of amphibians were artificially subjected to drying conditions experienced in milder form in nature. This paper presents (1) data based upon the careful measurement of the water lost through evaporation, (2) a comparison of the limits beyond which individuals of the species studied could not survive exsiccation, (3) a correlation

It was generally believed that the mechanical properties of carbon steel were remarkably changed by heat treatment. But, generally speaking, in the case that the carbon content was below 0.2% it was difficult to expect the effect of heat treatment. In this paper, the present investigators, therefore, made a study of the effect of the quenching temperature and coolant on formatitive condition of low carbon martensite in the mild steel with carbon 0.07% preceded by normalizing at appropriate temperature through means of hardness, impact and metallography test. A summary of the results is shown below : (1) Except for spindle oil, in order to produce the maximum quench hardening effect it is necessary to quench after keeping 10 minutes about 900℃, and it is unconcerned in coolant. (2) 10% NaCl solution is best for coolant. (3) Factors affected on Charpy's impact value on the quenched mild steel are not hardness but its structure and austenite grain size.

Skeletal morphology seems to be controlled not only by evolutionary heritage and necessities of adaptation to specific environments, but also by morphogenetic programs which often appear as non-adaptational elements of low taxonomic significance. Constructional morphology tries to find out how the three groups of factors are correlated in a given form. This article is the first of a series of papers in which these principles will be applied to different groups of organisms. Einleitende Bemerkungen zu einer Artikelserie, in der neben der historisch-phylogenetischen und okologisch-adaptiven Bedingtheit fossiler und fossilisierbarer Formen auch allgemeinere morphologische «Lizenzen» beleuchtet werden sollen.

The paper traces the beginnings of human culture in Africa, its evolution and spread, and shows the feedback relationship that exists between biological evolution and culture. It is demonstrated how environment is the most important factor in producing variability at the food-gathering level, and the present-day regional differences in culture are shown to have been in existence for some 40,000 years. The history of the introduction and spread of domestication is summarized, and evidence is adduced to indicate that the diffusion of Iron Age economy in southern Africa was due as much to adaptation as to immigration, thus demonstrating a real and traceable continuity up to the present day.

1. Our present information on non-genetic adaptation of intact aquatic organisms to temperature and salinity does not yet provide a sufficient platform for a detailed analysis. Only a few of the publications available deal with non-genetic adaptation exclusively; many are primarily devoted to other topics. The mechanisms of most types of adjustments appear to be rather complex and are not yet well understood. The net result of non-genetic adaptation is compensation for adversive aspects in a changing environment. 2. Non-genetic adaptation may involve quantitative changes in lethal limits, activity, metabolism, reproduction and other functions as well as in body dimensions, architecture of organs and cells, cell number per organ and in the quantity and activity of enzymes. It practically involves all levels of organismic function and structure. Non-genetic adaptation is not the result of a single process but represents a syndrome. The capacity for non-genetic adaptation depends on the genetic background of the organism involved; it may be different in different ontogenetic stages, such as egg, larva and adult, and may bear relations to metamorphosis and reproduction. There appears to be some evidence that non-genetic adaptations which have been acquired during the most sensitive phase of an individual's life cycle may be transferred to the next generation as non-genetic transmission (e. g.Prosser 1958). 3. There is urgent need for carefully conducted long-term experiments. Much of our present knowledge on non-genetic adaptation has been obtained from organisms kept under inadequate conditions; numerous experiments seem to have been conducted on sick or dying specimens. Even the small amount of information available at this time has therefore to be evaluated with some critical skepticism. Poor conditions and poor health are dangerous prerequisities for the analysis of such a complex and subtle process as is non-genetic adaptation. 4. Assessment of quantitative aspects of non-genetic adaptation requires distinction between its amount, stability and velocity. To illustrate this point, let us consider a euryplastic organism with a considerable capacity for non-genetic adaptation. In such an organism the amount of non-genetic adaptation tends to reach the highest values during early ontogeny and thereafter to decrease gradually with increasing age of the individual. The maximum amount of a given acclimation may only be attainable in individuals born and raised in the test environment. The amount may be expressed in “percentage perfection”. The perfection of a nongenetic adaptation is 100 per cent in the rare case of an “ideal” or “perfect” acclimation, i. e. if the steady-state performance following a significant change in temperature or salinity goes back to its original level after stabilization. In most cases the percentage perfection is much smaller. Thus in the crabPachigrapsus crassipes perfection of acclimation to a seasonal range of about 10°C (Southern California) was calculated byRoberts (1957) from rate-temperature curves for individuals acclimated to experimental temperatures to be about 30 per cent. The degree of stability of a non-genetic adaptation, too, seems to decrease with increasing age: adjustments during early ontogenetic development tend to be more stable than those performed during later periods of ontogeny and may even be — at least in part — irreversible throughout the rest of the life of the individual concerned. Examples areCrangon crangon (Broekema 1941),Gammarus duebeni (Kinne 1953, 1958b),Lebistes reticulatus (Gibson 1954,Fry 1957,Tsukuda &Katayama 1957,Tsukuda 1960),Cyprinodon macularius (Kinne 1962). Reversible acclimations need reinforcement if they are to be maintained. The velocity of non-genetic adaptation tends to increase with increasing rates of metabolism. In the fishCyprinodon macularius, for example, speed of acclimation increases with temperature and seems to be proportional to growth rate: fast-growing fish adapt faster than slow-growing ones (Kinne 1960, 1962). 5. Most authors have considered non-genetic adaptations to a single environmental factor, namely either to temperature or salinity. Organisms, however, react to their total environment rather than to single entities. It is therefore of particular importance to study the combined effects of two or more components of the environment. Very little is presently known about the combined effects of temperature and salinity on the process of non-genetic adaptation (e. g.Dehnel 1960,Todd &Dehnel 1960,Matutani 1962,Alderdice 1963,Kinne 1963b, 1964a, b).McLeese (1956) analyzed the combined effects of temperature, salinity and oxygen on the survival rates of American lobsters (Fig. 8) (see alsoAlderdice 1963), and at the present Symposium,Roberts (1964) reported that the perfection of thermal acclimation of respiration in sunfishLepomis gibbosus becomes a function of day length above temperature of about 10°C. 6. There appears to be some evidence that acclimation to one factor, say salinity, proceeds at different rates and at different efficiencies under different levels of other simultaneous acclimations, for example, to temperature or oxygen (Kinne 1964a, b). Furthermore, inharmonious interrelations between one functional or structural adaptate relative to another may be a fundamental way of limiting the total resulting amount of non-genetic adaptation. The maximum amount of acclimation to a given temperature is presumably only attainable at normal or near optimum salinities, and, conversely, maximum acclimation to salinity is presumably only possible under corresponding temperature conditions. 7. Very little is known about the process of de-adaptation. Does the process of de-acclimation display a similar or a different time course than the respective acclimation? Can de-acclimation from one factor, such as temperature, be initiated or hastened by applying a new stress, such as extreme salinity? De-acclimation may involve active changes and not just a cessation of a given non-genetic adaptation. Thus upon return from high altitude to sea level, erythropoiesis not only stops, but erythrocyte destruction is accelerated (Merino 1950). Apparently, acclimation and de-acclimation are two opposed processes in competition, reaching equilibrium only under constant environmental conditions. 8. The information presented in this paper pertains to reactions of intact, whole individuals. Can we expect cells, tissues or organs removed from multi-cellular animals to preserve and display the full amount of a given non-genetic adaptation acquired in the intact organism? Presumably not, if a substantial part of that acclimation is based on adjustments in organismic integration. But even in other cases, removed cells or organs may often tend to lose part or all of the acclimation acquired due to damages caused by operation procedures. Another important question is whether or not there exists a relationship between the amount of acclimation retained in isolated cells and (a) the level of organismic organization of the test organism (e. g. in the series plant, protozoan, crustacean, fish), or (b) the degree of disturbance caused by the removal of these cells. 9. The amount of cellular acclimation to a given environmental situation may very well be different in different tissues or organs. Thus non-genetic adaptation to changes in salinity may express itself in cells of epidermis, gill or gut rather than in muscle or nerve cells. InCordylophora caspia, for example, acclimation to different salinities results in considerable adjustments in the cells of tentacles, hydranth body and “neck”, while those of the hydrocaulus and stolons remain practically unaffected (Kinne 1958a), and in male rats, cold acclimation causes a remarkable increase in the amount of brown fat, while other tissues do not seem to show such intensive modifications (Smith 1964).

In the virtual absence of a fossil record, the origin and subsequent evolution of the venomous snakes must be inferred from our knowledge of their modern representatives. Evidence pertaining to this history has been accumulating since the days of Boulenger and Cope. However, the several interpretations of this evidence have led to conflicting phylogenetic schemes. These difficulties are to be expected from the limitations of the comparative method and the high degree of specialization by these snakes. The chief point of disagreement among the current and choice hypotheses is in the relationship between the Elapidae and the Viperidae. These families have long been regarded as independent derivatives of colubrid ancestry. The present paper is to introduce new evidence as to the relationships between the major groups of venomous snakes from a study of their vertebral characteristics. The results of this study, together with the evidence from other sources, indicate that the elapine and viperine stocks are intimately related. Enough evidence is available to suggest a course of the development of these families which will accommodate those features that have previously been regarded as ambiguous and inconsistent. In order to reconstruct a phylogeny such as this, we seek those morphological attributes that have remained relatively stable in time. Vertebral form among snakes exhibits such stability. In a recent study the writer has explored the adaptive significance of vertebral form in snakes (Johnson, 1954). Vertebral shape was expressed in twelve measures and these in turn were combined into ratios to provide the characters for quantitative analysis. Only those ratios that showed low intra-columnar variability were employed. With a sample of 57 snakes representing eight families, the association of vertebral variety with mode of life was tested. The results of this study indicated that vertebral form is remarkably stable. Little association of the characters with various modes of life was found. Further, an attempt was made to demonstrate the association of the characters with mode of life in one family, the Colubridae. The same results were obtained; the colubrids showed little divergence with respect to gross adaptation. An analysis of six families revealed that vertebral form reflected taxonomic relationships to a greater degree than mode of life. These results suggest that the variation of form expresses those primary adaptive tendencies correlated with the divergence of groups now recognized as taxonomic entities. This study provided an assessment of the reliability of snake vertebrae as a source of phylogenetic inference. With such a background the vertebral characteristics of the following families were studied

1. 1. The oxygen consumption at 15, 20, 25 and 30°C in microliters per hr per adult and per mg wet wt. is reported for Drosophila immigrans collected from a warm environmental and grown at 15 and 25°C. The stocks grown at 15°C have a higher rate of respiration at 20°C than those maintained at 25°C. 2. 2. The oxygen consumption is also reported for D. immigrans collected from a cool environment and grown at 15 and 25°C. The stocks grown at 25°C have a lower rate of respiration at 20°C than those maintained at 15°C. 3. 3. It is concluded that the widely dispersed D. immigrnas is eurythermal and flies from both warm and cool environments show a physiological temperature adaptation. 4. 4. A comparison of the oxygen consumption of the six species of Drosophila reported in this series of papers has been made with respect to temperature, sex and weight.

In this paper I attempt to answer the question, What (if any) differences occur in the foraging of isolated wood warblers (Parulidae) and ones in large multispecies populations? Parula (Parula americana), Myrtle (Dendroica coronata), and Black-throated Green (D. virens) Warblers were studied on seven small spruce-clad islands off the coast of Maine, each island supporting one pair of one to three of these species. Data obtained were compared with earlier studies of these species in large adjacent populations. Though seasonally isolated, all individuals belonged to the large gene pools of the appropriate species on the adjoining mainland. While the insular forests resemble those of the mainland, they are in general shorter and more open. When only one species was present, it was always the Parula Warbler; when two species were present, they were always the Parula and Myrtle. Black-throated Green Warblers only occurred in the presence of the latter two species. diversity increased as the size of forest and proportion of foliage in tree crowns grew. Parula and Myrtle Warblers experienced greater nesting success than Black-throated Green Warblers. Black-throated Green Warblers foraged much as they did in large populations; however, Myrtle and Parula Warblers demonstrated considerably more plasticity in foraging. When Black-throated Green Warblers were absent, the two other species tended to modify their foraging. On the one island studied in detail where only Parula Warblers occurred, they appeared to expand their foraging range farther than where Myrtle Warblers were present. Overlap in foraging usually decreased as species compositions became more depauperate. Though variability occurred among individuals of each species, variability of an individual in two different years appeared as great. Black-throated Green Warblers dominate the other two species socially, and the implications of this situation upon distributions in larger populations and on small islands are discussed. I hypothesize that the stereotypy of the Black-throated Green Warbler represents an adaptation to the extremely high density it experiences in large populations, which make up the major part of the gene pool. The higher degree of plasticity seen in Parula and Myrtle Warblers may be appropriate to their subordinate roles.

The teleost fishes live in two different environments, the fresh water of lakes and rivers, and the salt water of the sea. With few and unimportant exceptions, these habitats are, respectively, very much hypotonic and very much hypertonic to the fish blood. In both cases continual performance of osmotic work is required for the maintenance of the normal blood concentration. The vast majority of fishes are able to exist only in one type of environment, although some variation in that environment is tolerated. The most pronounced exceptions are various species of the eel, Anguilla ; other species showing similar but generally less ability include the salmon, the stickleback (genus Gasterosteus ), and some of the Cyprinodonidæ, notably species of Fundulus . All species of teleosts, apparently, show adaptive responses in blood concentration to slight changes in the salinity of the environment, and the work of many investigators, particularly Duval (1925) and Smith (1930), indicates that the adaptive responses and mechanisms in the eel differ only in degree from those in the osmotically less resistant fishes. The “chloride cells” of the eel gills discovered recently (Keys and Willmer, 1932), were found in all species of fish examined, and were present merely in greatest numbers in the eel.

Artificial propagation by seed of palatable native browse species may be an economical way of improving big game forage and watershed values. Success of artificial reseeding generally requires that the planted seeds germinate soon after growing conditions become favorable. On the other hand, under natural conditions, persistent and variable seed dormancy may often be a factor favoring survival of a species. Such dormancy is in no way uncommon among native browse and tree species. This adaptation, however well-geared to the timeless regime of nature, presents an obstacle to efficient artificial seeding of these refractory native species. It can be overcome only by learning the processes for unlocking the seed dormancy perculiar to each species. This paper presents effects of comparable seed treatments upon seedling emergence of seven browse species potentially important in the improvement of big game ranges and control of erosion throughout much of the northwest mountain region. Results from the tests show the extreme importance of proper seed treatment of these browse species if germination is to be hastened, and what some of the effective treatments are for each species. Most of the data support results from other studies, thus strengthening the base for generalizations. In a few instances, contradictions point up the need for more investigations.

Summary A somewhat revised classification of the Musophagidae, which is a by-product of the general review, is offered first, with summarized reasons, in order to facilitate discussion. Eighteen species are recognized in five genera, Gymnoschizorhis being sunk in Corythaixoides, and Ruwenzorornis, Proturacus and Gallirex in Tauraco. T. corythaix is regarded provisionally as highly polytypic, including persa and fischeri among other allopatric forms; but the absence of intermediates may mean that they are actually a superspecies. For each species the geographical and ecological ranges are defined as closely as possible, relying much on unpublished information and with special reference to cases of prima facie ecological overlap. The subspecific variation is also described. The third part of the paper deals with general features, with particular reference to adaptation and relationships. Evolutionary problems are raised especially by the pigments (the green turacoverdin is now shown to be, like turacin, a copper compound), by the nature of the nostrils and by the head-feathering. Finally, problems are discussed that are connected with ecological radiation and overlap, with the geographical ranges of the species and with the numerous cases, mainly subspecific, that suggest convergence.

The fermentation tests introduced by M. H. Gordon (1) in his study of streptococci isolated from saliva and some other sources were proposed by him as a means of differentiating among these organisms and separating them into definite varieties. Gordon’s methods were applied by A. C. Houston (2) in observations upon streptococci obtained from normal human fæces and from milk, and they were largely relied on by Andrewes and Horder (3) in their investigation of pathogenetic streptococci from disease in man.

IN a previous paper' the writer has attempted to show how the psychological mechanism involved in the aggregation and maneuverings of individual fishes in schools may probably be explained as composed of a very simple set of purely automatic reactions. Greater difficulties are met with in an endeavor to explain the phylogenetic or ontogenetic origins of these reactions. It is not a prior inconceivable that they should properly be regarded as manifestations of ontogenetically acquired habits, but their early appearance ill the life of the individuals and their more or less fixed relationship to definite systematic groups of fishes indicate the probability of their being based upon the phylogenetically developed, inheritable, nervous and morphological orgaiiization of the species after the manner of tropisms and sex instincts. With our present inadequate knowledge of the physical background for instinicts and nervous reactions, it is impossible to attempt any direct explanation for the evolution of the schooling "'complex,'" unless the theory of phylogenetic adaptation according to the requirements of the organism be dogmatically adopted as a necessary axiom of biology. But, granting the evolution of the schooling instinct as an inexplicable quality in the nervous organization of many fishes, we may be able to determine some of the factors influencing its varying degrees of manifestation in the different systematic or biological groups, by studying the relation

20. This matter was dealt with at some length in the verbal presentation of this paper. As far as I can tell, the idea was advanced first by L. van der Pijl, Fledermause und Blumen. Flora, 131: 1-40. See s. Ca bridge. Baker, H. G., 1963. Evolutionary mechanisms in pollination biology, Science, 139: 877-883, for a more extended consideration of the subject. 21. The financial assistance of the NSF is, once again, gratefully acknowledged. 22. Baker, H. G. 1961. The adaptation of flowering plants to nocturnal and crepuscular pollinators, Quart, Rev. Biol., 36: 64-73.

During a period of almost sixty yean from 1912–1969 there have been several observers of this ritual. In this paper Spencer's account of a kulama in 1912 is examined in detail to determine the nature of the ritual activities, for which a model of sacrifice is suggested. The modifications recorded in later accounts are then considered against this background. Although the more recent rituals lack the coherency of that of 1912, the kulama persists with some relevancy in the contemporary contact situation.

0 B S T E T R I c I A N s are concerned with fetal cardiovascular physiology whenever they listen to a fetal heart. The problem is to distinguish between “normal” and “distress” situations. With knowledge only of the physiology of the adult as a guide, it is little wonder that reliable criteria of fetal distress are not readily available. The purpose of this paper is to set forth the character of fetal cardiovascular control and to provide a basis for the interpretation of it. With this new concept in mind, the problems of intrauterine fetal life and of neonatal adjustments after birth come more clearly into view. With the fetus in utero, attention focuses on the effects of the loss of gravitational pull on the body. The more fundamental question involved is the basic physiology of antigravity mechanisms upon the body. From this \;iewpoint, the entire spectrum of the consequences of weightIessness on the organism may be seen. Then evidence affirming the broad concept of sensory deprivation in general upon the body, and of antigrakrity deprivation in particular, may be looked for. In their book, Kybunetics of N&u,-al Systems,’ D. and K. Stanley-Jones establish a case for the concept that physiologic systems which are in a state of dynamic equilibrium-as are all living things---arc under the control of built-in mechanisms

In this paper, variation and polymorphism in flowering plants will be illustrated by reference to the genus Viola and in particular to V. riviniana . This is a tetraploid species, probably allopolyploid, with a wide European distribution; it is found on soils of a wide range of base status and texture, and in both woodland and grassland communities from the lowlands to subalpine regions. The species is somewhat gregarious, and large populations are not uncommon. The aim is to indicate the complexity of the populations and of the factors which control them, rather than to single out one aspect for special treatment. Certain size characters which are plastic and probably polygenically controlled will be discussed first. Variation in these characters is not sharply discontinuous; it is correlated with habitat and can be regarded as adaptive. Phenotypic plasticity is common in flowering plants and it is clearly important in habitat adaptation. Thus a range of habitats can be occupied by a single biotype, as, for example, by certain microspecies of Taraxacum and Alchemilla which are obligate apomicts. Even in outbreeding species, populations from different habitats which differ in phenotype can sometimes be shown to differ little, if at all, in genotype. More commonly, however, such phenotypic differences are found to be partly under genetic control; and this is the case in Viola riviniana . Here, dwarf small-leaved forms are found in exposed habitats, such as grassland, and large-leaved and more loosely branched forms in sheltered habitats, such as woodland. Intermediates occur in intermediate habitats, and the series can be regarded as an ecocline. In cultivation under uniform conditions, the differences are diminished but do not disappear; and breeding experiments show that they have become genetically fixed. It would appear that genotypic response is buffered by the direct response of the phenotype to the environment; extreme genotypic specialization thus does not occur, and the process may be able to reverse itself fairly quickly should conditions change. In western Europe most habitats are at best semi-natural, and many have been extensively modified by man. The result is a patchwork pattern of plant communities which are rarely in a state of stable equilibrium; and changes from one type to another, e.g. from grassland to woodland, and vice versa, are frequent. It is likely that plants such as V. riviniana may be able to adapt themselves successfully to the rapidly changing conditions.

Two short accounts of the habits of pseudapocryptes lanceolatus were communicated by me to the Indian Science Congress and were published in the Proceedings of the Congress, Das (1930), Das (1932). There are 11 Indian genera of the family Gobiidæ which include 89 species. The genus Pseudapocryptes has been reported from the coasts of India, Burma, the Andaman Islands, and the Malay archipelago. The specimens of pseudapocryptes lanceolatus studied were obtained from the estuary of the Ganges, Chiefly from Port Canning and Diamond Harbour, not far from Calcutta. The fish is often brought to the Calcutta market and is especially abundant during the months of October and November.

SUMMARY. The paper deals with the biology of the marine and semi-marine littoral grapsid crabs of Jamaica. The ecological preferences of each species are described; they show considerable differences in diurnal activity, terrestrial adaptation and tolerance of reduced salinity. A reasonably full account of the biology of Aratus pisonii is given, the growth and breeding of Sesarma ricordi, Pachygrapsus gracilis, Pachygrapsus transversus and Cyclograpsus integer are discussed in lesser detail, while only short notes are included on the other species. The following are among the general conclusions reached. 1The moulting increments are smaller than in fully aquatic crabs. 2Puberty occurs over a small size range. Moulting afterwards continues indefinitely, and there is no terminal anecdysis. 3In some species the females can copulate and ovulate at any phase of the moulting cycle, in others only while freshly moulted. 4Breeding is continuous throughout the year. Some species produce eggs in each intermoult, others only in alternate intermoults.

While exact records of environmental factors such as edaphic features, temperature, light, water, and biotic relationships are essential in the determination of the character of plant habitats, such data serve merely as an introduction to the investigation of the adaptation or equipment of plants for living in specific locations. While certain external characteristics, such as small or dissected leaves, are associated with sun plants, and broad leaves with shade plants, histological study reveals in greater detail any modifications of the normal type of tissues which are known to perform special activities. That the activities pertaining to the life processes of the plant are closely associated with its use of water is a well known physiological fact, so that not only the available water of the habitat but that which the plant actually uses or what passes through it in the transpiration stream is an important indicator of its toleration of conditions peculiar to its particular habitat. Work has been done by Livingston, Bakke, Shreve, and others on the transpiration of plants, and Bakke (i) has proposed a classification of plants as xerophytes, mesophytes, or hydrophytes on the basis of transpiration, which it seems is a very exact indicator of the available water used. While indices of transpiration would no doubt be desirable in connection with a morphological study, and would probably throw some light on whether a special type of tissue were characteristic of a species because of reaction to habitat or because of ancestral influence, the observations reported in this paper are confined to the morphological phase alone.

This paper reviews research published since the Cold Spring Harbor Symposium of 1960 on “Biological clocks”. It is concluded that, despite annual increases in the quantity of research which have appeared since then, knowledge of the fundamental physiology of rhythms has progressed relatively little. Adaptive functions have fared even worse. It is probable that no single explanation of the diurnal vertical migration of plankton will ever be found. There has, however, been further evidence for the role of circadian rhythms in relation to physical factors of the terrestrial environment. These include water conservation among invertebrates and thermoregulation in poikilotherms. The interaction of such factors is discussed in relation to photoperiodism. Biotic factors in which rhythmic activities are of importance include reproduction, feeding, escape from enemies and, presumably, competition, although there appears to be little factual evidence for this. Finally there is a discussion of the adaptive ...

In the course of previous investigations, Dix, Hallpike, and Hood have concluded that the phenomenon of loudness recruitment is attributable to disordered function resulting from injury or disease of the hair cells of Corti's organ.In the present paper, an account is given of an experimental study of certain loudness changes caused by adaptation of the hair cell responses to pure tone stimulation.Two outstanding characteristics of the adapted state are defined: “on‐effect normality” and “relapse.” Both resemble very closely those described by Matthews in the case of adaptation occurring the muscle stretch receptors of the frog.Further studies in a number of human subjects show that both of these characteristics are exhibited regularly by the unadapted hair cell responses of individuals suffering from degenerative changes of the hair cells.These studies appear to establish a very close similarity between “on‐effect normality” occurring in the case of the adapted normal sense organ and the phenomenon of lou...