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Young Homarus vulgaris were reared in the laboratory up to stage V. All settled during stage IV by burrowing under stones placed on a sand or mud substrate. Half of the 100 animals studied burrowed within 6 days of reaching stage IV and did not subsequently vacate the burrow. The burrows were made with two openings on opposite sides of the stone which, in the case of the sand burrows, served as a roof. The burrows were made by the same methods as previously described for young and adult H. americanus

Pagurus longicarpus (Say) migrates in autumn from a shallow estuary to deeper waters of Narragansett Bay, Rhode Island, when ambient water temperatures are between 10? and 4? C. Critical thermal minimum experiments indicated that crabs ceased locomotor activity at approximately 30 C and righting response at 1.5? C. When presented with different sub- strates, crabs used their walking legs and, occasionally, their chelae to scoop a depression in the substrate. They were not able to construct a proper depression in gravel and, although they succeeded in burying themselves in both mud and sand, they remained buried only in sand. Winter dredging seaward of an estuary in which hermit crabs were found in summer showed the greatest density of crabs at 16-18 m depth, buried in fine sand. No crabs were found several meters away at 20 m on a silty mud bottom. The water temperature was less than 20 C in all areas sampled. It is hypothesized that, as environmental temperatures decrease, hermit crabs move into deeper water and bury themselves in regions of sandy bottom. Overwintering in this manner might decrease the predation of hermit crabs by benthic organisms while the crabs are in a state of torpor.

Analysis of water and sediments collected at two stations in Chesapeake Bay demonstrated four to five times the concentration of petroleum in an oil polluted site in Baltimore Harbor compared with the station in Eastern Bay which served as a control. The numbers of petroleum-degrading microorganisms, measured by direct and replica plating, in the water and sediment samples were related to the concentration of oil in each sample. Total yields of petroleum-degrading microorganisms grown on an oil substrate were greater for those organisms exposed to oil in the natural environment. Microorganisms isolated from an oil-contaminated environment produced cell yields under “natural” conditions, i.e., laboratory simulation of growth conditions in the natural environment, which equaled the yields of microorganisms which had not been previously exposed to oil and were grown under optimum conditions. Microorganisms isolated from water and sediment samples collected in Baltimore Harbor grew on substrates representative of the aliphatic, aromatic and refractory hydrocarbons. The hydrocarbon-utilizing fungus, Cladosporium resinae and actinomycetes were predominant among the hydrocarbon-utilizing isolates. Microbial degradation of petroleum in Chesapeake Bay appears to be mediated by the autochthonous microbial flora, the seasonal incidence of which is presently under study.

Hydroquinone when added to the aquarium water was found to be about a hundred times more toxic than phenol, to goldfish (and to Daphnia magna), but is only about twice as toxic when injected into fish or mammals. Tertiarybutyl catechol shows a similar high toxicity in the aquarium, while the toxicity of catechol, resorcinol, and pyrogallol approaches more closely that of phenol. As the substances of high aquarium toxicity are known to inhibit many oxidative and polymerizing autocatalytic "chain reactions," rank correlations were tabulated between the recorded inhibitory potency of various substances in these processes, and their aquarium toxicity for goldfish. The correlation between aquarium fish toxicity and electric oxidation potential (P 0.09) is more than suggestive, and becomes still more so if explainable discrepancies are excluded. Antioxidant fat stabilizers show suggestive correlation with fish toxicity (0.20), and better with electric oxidation potential (0.10). The photographic reduction potential gives suggestive correlation with fish toxicity (0.20) and somewhat better with the oxidation potential (0.15). The gasoline induction period correlation is more than suggestive with the oxidation potential (0.099), but rather poor for fish toxicity (0.265). The rubber anti-aging potency gives only poor correlation (0.39) with fish toxicity. The reasons for these divergencies are not clear; they may perhaps be connected with the solvent properties of the substrate. As an example, Lea (p. 175) cites that 0.01 per cent of maleic acid prevents rancidity of fats, but is rendered ineffective by the presence of water. Taken by themselves, no one of the P values is entirely convincing of the relationships stressed in this paper. However, the consistent finding of relatively small values of P lends considerable weight to the hypothesis that these chemicals act in a related manner; and that the chemical activity of a substance may furnish useful suggestions of its biologic potency, perhaps more so than the chemical constitution as such. The aquarium toxicity, for goldfish is a convenient means of classifying the biologic potency.

The interstitial archiannelid, Protodrilus hypoleucus Armenante, selects sands coarser than 0.25 mm particle diameter. The natural gravel containing P. hypoleucus has an attractive property which can be destroyed by drying, heating to 60°C, acid-cleaning and treating with alcohol, formalin and cetyltrimethylammonium bromide. By soaking unattractive autoclaved gravel in normal sea water for two weeks the attractive property is regained. Inoculation of autoclaved gravel with naturally occurring gravel bacteria brings about a complete restoration of the attractive property. Not all types of bacteria bring about the restoration of the attractive property. Natural sand bacteria were preferred to Corynebacterium enythogenes which in turn was more attractive than Flavobacterium, Serratia marinorubra and the sterile control. The distribution of P. hypoleucus is therefore thought to be due to selection of a substrate having a surface film formed by favourable species of bacteria.

The marine tube-building polychaete, Owenia fusiformis, selects sand grains of tablet form for its tube. It can concentrate the mineral hornblende at least 25-fold and these concentrations may persist after the death of the worm. Owenia and a small anemone, Zaolutus actius, can act together to stabilize the sand surface against movement by wave surge. The result is the formation of an area of stabilized substrate, with which characteristic animals and plants are associated, in the midst of a region of shifting granular substrate.

1.Protodrilus rubropharyngeus Jagersten, a marine interstitial archiannelid, was found to move to the surface layers of sand in response to a negative geotaxis and preference for areas of highest oxygen tension. 2. Strong light and vibrations tend to keep the animal just below the sand surface except on calm days. 3. The adults were found to be highly gregarious. 4. Both adults and larvae showed a preference for the 0.5 to 1 mm grade of sand. 5. The localisation of high numbers of animals in narrow areas of a uniform beach seems to be related to the presence of a localized surface film on the sand grain surfaces. This film is produced by certain favourable species of bacteria, and together with a chemical produced by the animals themselves, attracts other members of the species to this sand.

The distribution of nutrient salts in plastic pots on different types of subirrigation benches has been studied. Moderate amounts of nitrogen and potassium in the water supply led to a considerable accumulation of salts over a relatively short period of time. This accumulation was largely concentrated in the upper layers of the pots. A marked accumulation also occurred on benches with free drainage of the substrate.

1. 1. Cirriformia spirabrancha (Moore, 1904) maintains its coelomic fluid slightly hyperosmotic to the blood over the range of salinities tested. 2. 2. The salinity tolerance limits of C. spirabrancha as determined by the ld 50 values are 23% and 220% sea water. These limits were slightly reduced for worms placed in the external medium without substrate. 3. 3. Volume changes for animals in various concentrations of sea water and in solutions composed of osmotically equivalent amounts of sea water and sucrose indicate that this polychaete reaches equilibrium to hyperosmotic media by a means not totally dependent upon water loss. This property may account for the observed tolerance to high salinities.

The shallow Kuznets Basin had 3 distinct marine facies zones during the Carboniferous. The open sea Zone contained detrital carbonate sediment, and a varied fauna dominated by relatively large brachiopods, with productids and spiriferids most numerous. As this zone enlarged and diminished throughout the history of the basin, the characteristic fauna expanded and contracted accordingly. Details of this history are traced and illustrated in the text. The intermediate facies zone contained greater variety of sediments, and correspondingly more diverse and complex faunal assemblages. Brachiopods were small; those in quiet water areas lived unattached on the soft substrate, or attached by pedicles to algae. Where grain size of sediment allowed, some attached directly to the sea bottom. In more agitated waters corals and unattached brachiopods are absent, and the fauna scant. The shoreline facies zone contained coarse sediments, and only a few ostracodes are preserved. Species or genera with the narrowest strat...

Penitella penita , a west coast rock-boring clam, forms a conical burrow in the rock the shape of which is controlled by a number of environmental variables. The most important of these being substrate hardness. A method for determining the relative friability hardness of sandstone is described. The possibility that this information could be used by the paleontologist to establish the hardness of sedimentary rock at known times in the past is discussed.

Three size groups of Stagnicola palustris nuttalliana and Physa propinqua were exposed to six water velocities, between 0.5 and 3.0 ft/sec., in a plexiglass flume on six different substrates. The snails were tested for ability to remain attached to the substrate and the data analyzed by a factorial analysis of variance. The middle—size group of snails was dislodged easier than the older two size groups. Stagnicola was less easily dislodged than Physa. The greatest dislodgment occurred from sand, followed by clay, caliche rock, plexiglass, pea gravel and basalt rock. Increased water velocity caused greater dislodgment. See full-text article at JSTOR

1. Germination of seeds in the pots having a high calcium carbonate content (pH 8.0) began about a week after that in the pots having no calcium carbonate (pH 5.6). 2. Thirty-five days after planting, the secondary roots formed at the time of germination continued to live in the minus calcium carbonate series, while there were few or none when calcium carbonate was present. 3. The average length of roots was almost twice as great when calcium carbonate was present as when absent. 4. Ninety days after planting, top growth of grass grown on a substrate having a high calcium carbonate content was, on the basis of dry weight, approximately 33 per cent greater than when calcium carbonate was absent. 5. When the effects of temperature and calcium carbonate are considered, it is found that at 15⚬ C. the presence of calcium carbonate is associated with an increase of 77.3 per cent in dry weight, and at 25⚬ C. with 135.6 per cent, calculations being based on the dry weight of 100 seedlings. 6. Data indicate that c...

Summary Soil moisture and soil pH determinations were made in the Afroalpine belt of Mt. Kenya between 3,780 m and 4,480 m, and the pH of free water samples was also found. A range of pH tolerance is suggested for some giant species of Lobelia and Senecio, and comparisons are made with other published data.

Techniques are described which allow the direct observation of water bacteria in their unchanged environment. Bacteria attaching to and growing on glass slides were observed with a partially submerged light microscope. Similarly, undisturbed living bacteria were studied in previously submerged PERFIL'EV glass capillaries, a necessity in the case of the fragile Gallionella or Metallogenium spp. Many new bacterial forms and surface structures were discovered when formvar-coated electron microscope grids were used as the substrate for attached growth („Aufwuchs”). Several water bacteria can be obtained by covering slides with layers of agar media and coating these with thin, transparent plastic foil to encourage specific attachment. The foil was used like a cover slip on water agar-coated slides. After microscopic observation the foil was peeled off and the colonies observed previously could then be isolated. Growth of pure cultures was successfully attempted in disposable Nalgene membrane filter units or in membrane-covered chambers which had been submerged in the aquatic environment to facilitate nutrient and waste exchange with the outside. Natural bacterial populations could be transferred with only little disturbance from stratified sediments to the laboratory. This was achieved by keeping aquaria in the water for an extended period of time to allow for re-establishment of the normal layering. During transportation, the aquaria were covered with plastic plates. In the laboratory some of the environmental factors such as the proper temperature and light were restored. With this method layered populations of even rare water bacteria could be kept alive for several months. Finally, an agar diffusion gradient plate is described. It enables one to grow and isolate unusually demanding, i.e. „stenobiotic” bacteria.

Participation in the Tektite man-in-the-sea experiments provided a unique opportunity to observe bioturbational rates and effects in carbonate sand at depths ranging from about 10-20 m near a coral reef. Experimental studies established the rate at which organisms in this environment modify the surface, disturb the interior of the sediment, and undermine solid objects on the sea floor. Inactive sand ripples are totally destroyed in 2-4 weeks. Lamination in the upper 2 cm is largely obliterated in the same amount of time. Pebbles on the sea floor can be buried in a few days by faunal undermining. The rate and style of bioturbation are strongly controlled by grain size of the substrate: surface modification and pebble burial are most rapid in relatively fine sand, whereas the rate of shallow internal disruption of the sediment may be more rapid in coarser sand. Bioturbation in this environment results largely from activity during daylight hours. A prodigious amount of sediment can be moved vertically or lat...

Lower Lias sediments from the Danish island of Bornholm exhibit many sedimentary indications of tidal influence during their deposition. A section in the Sinemurian is interpreted as a regressive tidal flat with supratidal salt-marsh (coals and rootlet-beds), tidal flat (flaser- and wavy-bedded clays and sands), tidal creeks, storm scours and sand sheets, large scale metaripples and subtidal sand bars. The lack of calcareous fossils is probably due to post-depositional leaching in the uncemented sediments; but the scarcity of burrows and the lack of fauna may also reflect a reduced overall salinity, or the often unstable (thixotropic) substrate conditions. The presence of tidally influenced sediments on the margins of the Lias epeiric sea in Europe demonstrates that tidal effects should not be ignored when considering aspects of epicontinental sedimentation in the Mesozoic of Northern Europe.

The effects of water motion on the attachment of algal germ cells to benthic substrates were studied. Water motion was measured in the field and the forces on a germ cell attached to a substrate surface computed. Laboratory apparatus for simulating wave surge was developed, calibrated, and used for experiments on the spore attachment process. A “waterbroom,” producing water motion over the surface of a submerged substrate in a laboratory aquarium, closely simulates wave surge; it was calibrated by measuring static and dynamic pressures in the substrate’s boundary layer and determining whether the layer was laminar or turbulent. Preliminary tests with the waterbroom indicate that the adhesion of carpospores of Agarrlhielln tenera to a clean glass surface increases wih residence time, while that of Cryptopleura violacea decreases. Improved experimental data on Gracilariopsis sjoestedtii showed an increase in adhesiveness with residence time, from 10 hr to an asymptotic limit at 20. Once attached, the Gracibariopsis spores adhere firmly, resisting removal by shear

Steam sterilization increased the yield of tomatoes grown on peat over 3 years. The increase becomes more pronounced with time. The effect of steaming was greater in the summer crop which has a duration of 6 months than in the autumn crop which has a duration of 4 months. Similar yield patterns were evident in tomatoes grown in sand and soil. Manganese levels in the growing media and in the foliage rose as a result of steaming, but toxic levels were reached only in plants growing on steamed soil which caused yield reduction. Leaf nitrogen content was increased as a result of steaming. Steaming over three years did not cause a breakdown of the structure of the peat.

An artificial diet was developed for the adult stage of Diabrotica undecimpunctata howardi Barber and was used to sustain a laboratory colony for over a year. Black aquarium gravel was found to be a practical oviposition substrate for use in conjunction with rearing larvae on artificial diet. Eggs could be readily removed from this medium with sieves and surface-sterilized with sodium hypochlorite. Over 40% of the newly hatched larvae placed on the artificial diet used for the larval stage successfully completed larval development in 20 to 21 days, Larval cannibalism occurred, and over ⅓ of the larvae placed on the diet were eaten by other larvae. Following completion of immature development, larvae were transferred to a mixture of dampened vermiculite and sand for pupation, Slightly over 60% of the larvae placed on this substrate emerged as adults in 16 to 24 days. With the diets and techniques described, about 25% of the 1st-stage larvae survived to become adults. Approximately 59 days were required for completion of a generation.

1. 1. An area of the skin specialized for water uptake was found in the pelvic region in Bufo bufo , Rana esculenta , R. arvalis and R. temporaria , but not in Xenopus laevis . 2. 2. In this specialized area, vascularization is more dense than in the rest of the skin. 3. 3. On a moist substrate, the water uptake in B. bufo after dehydration was higher than in Ranidae. The higher rehydration rate in B. bufo is explained by the presence of tube-like grooves on the surface of the skin acting as capillaries. 4. 4. When kept permanently in water, B. bufo exhibited a lower water uptake than toads kept on dry filter paper with free access to water.

The Okefenokee Swamp, a paludal region of over 400,000 acres is developed upon a terrace which was formerly a Pleistocene marine lagoon separated from the open ocean by a long barrier island (now Trail Ridge). Peat has developed in this region to a maximum depth in some places of approximately 15 ft. Nine peat cores taken within the Swamp with a piston-coring device were selected for detailed paleobotanical and petrographic analyses. The lack of any salt tolerant plants in the peat at the contact with the sandy substrate suggests that some considerable length of time occurred after withdrawal of the sea and before production of the first peats. Also the fact that the first-formed peat in all cases was a highly oxidized deposit containing residual siliceous material indicates that some thickness of previously deposited peat may have been destroyed before the onset of modern peat deposition. Paleobotanical analyses of cores from the three largest marshes (Chase Prairie, Grand Prairie, and Floyd's Prairie) reveal that these areas have not changed greatly in vegetational and depositional environment from the beginning of peat formation in the Okefenokee. In addition, the present positions of these prairies seems to be controlled by the positions of pre-peat topographic lows. Their vegetational continuity to the present day is probably related to: (1) a continuous, uniform rise in water table; (2) the common occurrence of fires in the Okefenokee; and (3) the consistently greater depths of peat in these regions. In this region, fires were found to have played an important part in the history of peat development. These burns were recorded in the cores as zones of abundant charcoal and residual, siliceous, fresh water sponge spicules.

The formation of 3,3′,4,4′-tetrachloroazobenzene from the herbicide propanil (N-(3,4-dichlorophenyl)propionamide), and from 3,4-dichloroaniline was studied in nine soils which varied in pH, percentage of organic matter, clay, and sand. Marked differences were observed in these soils in the amounts of azobenzene formed. In five soils whose pH values fell within a range of pH 4.5 to 5.5, azobenzene was produced from both substrates, while in two soils (Guelph loam and Wendigo loamy sand), azobenzene was only detected from 3,4-dichloroaniline. No azobenzene was detected from either substrate in two additional soils (Belleisle marsh soil (site 22, pH 3.4) and Biz silt loam (pH 6.4)). Air-drying soils, as well as extended periods of storage of freshly collected soils at 4 °C, reduced the formation of azobenzene.

TRIDACNID clams can be divided into two distinct groups on the basis of whether they are physically fastened to the substrate. Of the six species comprising the family Tridacnidae1, Tridacna crocea, T. maxima and T. squamosa live byssally attached to dead coral, coral rubble or limestone during the whole of their adult lives. The other species, T. gigas, T. derasa and Hippopus hippopus, live byssally anchored as juveniles, but when approaching maturity their byssus glands atrophy, and the adult clams take up unattached existence on coral rubble or hard packed sand. This habitat difference is also expressed in the weight and morphology of their shells. The byssally attached species possess shell valves which are in most respects larger editions of those found in other bivalves (Fig. 1 A). The unattached clams, on the other hand, possess bizzare shells which are unusually massive resulting from a unique deposition of solid shell material within the cavities of the umbones (Fig. 1 B).

Juvenile sand dollars (Dendraster excentricus) selectively ingest heavy sand grains from the substrate and store them in an intestinal diverticulum which may function as a weight belt, assisting the young animal to remain in the shifting sandy environment. The sand disappears from the diverticulum when the animal reaches the length of 30 millimeters.

The survival of vegetation in dune regions ordinarily depends upon a species plasticity which permits one or more of several possible adjustments to moving sand. A dune tolerant plant can usually endure temporary complete or permanent partial burial of the crown, elongate beyond accumulating drifts, greatly increase absorptive surface, withstand extensive exposure of the root system, or check the undermining action of wind erosion. Burial of vegetation, which usually results in defoliation and death, in certain plant species causes stem elongation which keeps young foliar portions of the crown sufficiently aibove the sand surface for survival. Such stems ordinarily produce adventitious roots at any level covered by moist sand. Certain species anchor the drifting substrate by a tangled growth of stems or roots. A number survive by the meristematic activity of creeping rhizomes. A few, chiefly the annuals, propagate successfully on and between the dunes by seed alone. The present study was initiated to discover gross modifications, especially in the main axes, of plant species growing in the nitrogen deficient gypsum dunes of the White Sands south and west of Alamogordo, New Mexico, and to compare this flora with that of certain quartz sand dunes. Locale.-This drifting gypsum deposit, which covers approximately 224 square miles, differs from the usual dune area in that the substrate is 96-97% calcium sulfate (Coville and MacDougal, 1903; Byers, 1936). Over a range approximately 28 miles long and 8 to 10 miles wide brilliantly white dunes 20 to 40 feet high alternate with narrow, wind-formed hollows. Windward slopes are long, rising gently at about a 300 angle, while leeward slopes are formed by sand slipping over the dune crests and settling at an angle of approximately 700. The darker, lighter weight impurities are blown free of the drifts where the winnowed gypsum, being heavier, remains. The water table in the flats lies 2 to 3 feet below the surface, and the pH of the substrate is 7.5 (Byers, 1936). Only one of the several soil chemists who have analyzed this gypsum sand reports any trace of nitrogen. Quantitative tests also indicate insufficient amounts of potassium and phosphorus for normal plant growth. Evolution of the dunes.-The White Sands lie in the Tularosa basin, which at this point contains gypsum carried from the Chupadora formation in the mountains on either side and deposited as valley fill, much of it in standing water, to a depth of 1000 feet (Potter, 1938). Gypsum forming the gradually growing dunes continues to 'be derived by wind excavation of an adjacent alkali flat, which represents the surface of the original de

Three size-groups of soft-shell clams,Mya arenaria, averaging 45, 60, and 74 mm in shell length were placed in aquaria and their rate of reburrowing measured. The substrate in each aquarium consisted of sand particles: (I) less than 0.5 mm, (II) 0.5 to 1 mm, (III) 1 to 2 mm, (IV) 2 to 4 mm, and (V) an equal combination of the previous 4 sizes. New specimens were tested at every 5 C rise or fall in ambient water temperature and observations were made periodically for 48 hours. The three variables, water temperature, clam size, and sediment particle size were highly significant (1% level), in influencing clam reburial activities by the end of the second hour through the termination of the experiment 48 hours later. Optimum water temperatures for reburrowing were between 8.8 and 21 C. After 48 hours, 62% of the small, 39% of the medium, and 21% of the large clams had reburrowed in all experimental tests combined. The aquarium with less than 0.5 mm substrate particle size had the greatest percentage of reburrowed clams of each size. As the particle size increased, progressively less reburrowing took place. Most reburrowing took place between 4 and 8 hours after the start of the experiment.

In summer, adult Rana ipipens, which normally reside at considerable distances from ponds, depend upon soil moisture as their primary source of water. Water is absorbed through the skin of the groin while sitting on the damp soil. Under controlled laboratory conditions leopard frogs dehydrated to 65-75% of their hydrated weight, can, on the average, completely recover the lost water in 48 hr when on sand with a moisture content of 20%; on sand with only 10% water content, only about 50% of the lost water is reabsorbed in 48 hr.