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ON JUNE 3, 2000, the National History Day (NHD) community was saddened by the sudden loss of David Van Tassel, NHD's founder. Although we mourn his loss, we also celebrate his life and legacy. I cannot think of anything more powerful or exciting than to have an effect on a young person, to change a life in some positive way-to watch the light bulb go on and to feel that you had something to do with that. David Van Tassel did that for millions of young people through National History Day. His influence extends to the barrios of Los Angeles, to inner-city Houston, to Navajo and Lakota Indian reservations, to small, rural mid-western towns and to wealthy and middle class suburbs. Through National History Day, David created a vehicle to reinvigorate the teaching and learning of history. But more important than that, what he produced was something that truly changes lives. It all began in 1974 when, concerned about the devalued nature of history in the nation's elementary and secondary schools, David Van Tassel, professor of history at Case Western Reserve University in Cleveland, Ohio, sought to bring the past to life for students and teachers. His idea was a competition through which middle and high school students present historical research in papers, table-top exhibits, dramatic performances, and multi-media documentaries. These products would be en

"West Hills is a romantic and beautiful spot... The 'high hill' affords an extensive and pleasant view... A view of thirty or forty, or even fifty miles, especially to the east and south and southwest; the Atlantic Ocean to the latter points in the distance-a glimpse or so of Long Island Sound to the north."-Walt Whitman, 1850. "... I was born.. . in the fertile meadow land [where today there is] rich corn in tassel, many fields; they had cradled wheat and rye, and... oats."-Walt Whitman, 1881.

Field experiments on the within-plant distribution of larvae of the fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), on the early-whorl to late-whorl stage of corn, Zea mays L., revealed that most larvae were found in the wrapped leaves of the whorl. Beta density function for describing larval distribution showed that larval instar, infestation date and environmental conditions did not influence this process. Larval distribution and its time course was accurately described with a single Beta density function for all infestations. This function gave 64%, 25%, 8%, 2% and 1% of larvae in the highest visible leaf and leaves just above, respectively. When the tassel began development in the whorl (pre-tasseling corn stage), most larvae (80%) were found in this location. After tasseling, larvae moved down to the lower leaves and into the ear (75%).

Teopod 2 (Tp2) is a semidominant mutation of maize that prolongs the expression of juvenile vegetative traits, increases the total number of leaves produced by the shoot, and transforms reproductive structures into vegetative ones. Here, we show that Tp2 prolongs the duration of vegetative growth without prolonging the overall duration of shoot growth. Mutant shoots produce leaves at the same rate as wild-type plants and continue to produce leaves after wild-type plants have initiated a tassel. Although Tp2/+ plants initiate a tassel later than their wild-type siblings, this mutant tassel ceases differentiation at the same time as, or shortly before, the primary meristem of a wild-type tassel completes its development. To investigate the relationship between the vegetative and reproductive development of the shoot, Tp2/+ and wild-type plants were exposed to floral inductive short day (SD) treatments at various stages of shoot growth. Tassel initiation in wild-type plants (which normally produced 18 to 19 leaves) was maximally sensitive to SD between plastochrons 15 and 16, whereas tassel branching was maximally sensitive to SD between plastochrons 15 and 18. Tassel initiation and tassel morphology in Tp2/+ plants (which normally produced 21 to 26 leaves) were both maximally sensitive to SD between plastochrons 15 and 18. Thus, the constitutive expression of a juvenile vegetative program in Tp2/+ plants does not significantly delay the reproductive maturation of the shoot.

This study was to determine effects of wiight lighting on plant development and production of field corn (Zea mays L.). Night light was provided by lamps on poles with reflectors directing the light on the corn. Corn grown under 0, 11, 55 and 110 lux of night lighting during 1971 was progressively taller, matured progressively later, and produced progressively higher forage yields. Corn grown in 1972 was increasingly taller and increasingly delayed in maturity from treatments of no night light through 15 minutes of light per night from enwrgence to tassel differentiation, light all night from emergence to tassel differentiation, and light all night throughout the season. Trans. Kans. Acad. Sci., Vol. 77 (2), 1974. INTRODUCTION Light is one of many ecological parameters that affect plant growth. Crop yields have been increased by supplementing such factors as water and fertilizer. Crops' light requirements also have been increasing. Growth rate of corn is closely associated with the amount of light it intercepts and its leafarea (1,6). Only about 5 % of the sun's visible light reaches theground in adense standof corn on aclear day (7). Supplemental lightcan be provided by additional daylight intensity or by light at night. Using sunlight reflectors to produce a "light rich" environment during the day has increased corn yields (4,5). Light at night lengthens the time for photosynthesis. However, lengthening the photoperiod delays tasseling in sensitive strains of corn (2,3). This experiment was to determine effects of night lighting on plant development and corn yield of field corn (Zea mays L.). Methods and b1aterials A General Electric3 400 watt multi-vapor lamp was placed atop a 7 meter pole in an irrigated corn Sleld near Oighton, Kansas, in 1971. A bat-wing reflector directed the light downward and outward4. Corn was planted in 76cm rows May 13; the light was first turned onJune 7 when the corn (DeKalb variety 1006) was about 25 cm tall. The lamp was used each night until early September. A photo cell turned the lights on during the night. Corn from 4.6 m2 areas receiving 0, 11, 55, and 110 lux of night lighting (approximately 13, 23, and 38 m from the light source, respectively) were harvested September 9, although the corn was not yet mature. Transactions of the Kansas Academy of Science, Vol. 77, No. 2, 1974. Published August 15, 1975. tContribution No. 115, Garden City Branch Experiment Station, Garden City 67846 and 1362, Agronomy Department, Kansas Agricultural Experiment Station, Manhattan G6506. 2Research Agronomist, Grden City Branch Experiment Station and Research Agronomist, Agronomy Department, Kansas State University. 3Use of product names does not imply endorsement over similar products not named. 4Electricity was supplied by lane-Scott Electric Cooperative, Inc., Dighton, Kansas.

An average of 14(7-34) plants each for 61 different collections of Zea (maize and its wild relatives, the teosintes) were studied for 12 enzyme systems coded for by 21 loci. Principal component and cluster analyses based on allele frequencies showed Zea can be divided into two major groups: 1) sect. Luxuriantes, including Z. perennis, Z. diploperennis, and Z. luxurians; and 2) sect. Zea (in part), including Z. mays subsp. mays, var. parviglumis, and subsp. mexicana. Zea mays var. huehuetenangensis (Huehuetenango teosinte) is isoenzymatically distinct from both sections, but shows its closest relationship to Z. mays var. parviglumis of sect. Zea. Populations of Z. mays subsp. mexicana and var. parviglumis grade isoenzymatically from one into the other without any clear break, but without any overlap either. Five populations of Z. mays subsp. mays are all isoenzymat- ically very similar to Z. mays var. parviglumis. The isozyme data are consistent with the theory that Mexican annual teosinte is the ancestor of maize. With the exception of the unusual isoenzymatic nature of Z. mays var. huehuetenangensis, the isoenzymatic data agree with previous studies of tassel morphology and cytoplasm DNAs. A comparison of sympatric populations of maize and teosinte suggests that teosintes are not greatly affected by introgression from maize. Zea mays var. parviglumis and Z. diploperennis have considerable within and among population variation; Z. luxurians has much less. Race Central Plateau of Z. mays subsp. mexicana has greater among population variation than any other taxon in Zea. Zea tends to show greater within population heterozygosity and more variance within species and subspecies than most other plants that have been studied isoenzymat- ically.

be traced to the infestation level of the earworm. Dusts especially are more effective when the infestation is light or moderate than when it is severe. However, DDT-oil emulsion sprays have at times also shown considerable variation in effectiveness even when they were apparently timed and applied properly. Barber (1943) brought out the fact that the earworm moth will oviposit on all parts of the corn plant. His studies showed that "larvae that hatch from eggs laid on plants before silks are exposed feed on whatever parts of the plants are most attractive at the time of hatching, the most suitable of which are the tender leaves of the whorl and the green tassel." He states further that "these larvae may migrate to the ears over a period of several days and they offer one of the greatest difficulties in the control of the insect in the ears." However, with the development of better methods of applying DDT-oil emulsion sprays, these migrating larvae have not been difficult to control. Chamberlain (1951) found that the earworm could be controlled in South Carolina in spring-planted corn with sprays applied after the corn began to silk, but that two pre-silking sprays were necessary for summer-planted corn because infestation was occurring before the silks appeared. With the addition of pre-silking sprays to those applied after silking, excellent control of the earworm was secured with a DDT-oil emulsion. In the Lower Rio Grande Valley of Texas, the first fields to come into silk in any particular area often have had small earworms in the silk channels of young ears before any silks emerged. In most cases these appeared to originate from eggs

Two very different varieties of popcorn, Ladyfinger and Tom Thumb,' have been extensively confused in agronomic and genetic literature. While the correct naming of popcorn varieties is a matter rather outside the ordinary realm of scientific endeavor, these two varieties have been so frequently used in genetic and breeding experiments, East (1911), White (1917), and Kempton (1926), that it seems worth while to describe and differentiate them. Aside from small kernels and small cobs the two have almost nothing in common. Each represents a morphologically extreme type among the readily available United States varieties of Zea Mays; for that very reason both may be of potential importance in practical breeding programs as maize breeding becomes even more scientifically expert. A few of the outstanding differences between these two varieties are shown in Table I. Even though the varieties have been confused because both have small ears and small kernels, they are readily distinguishable even by these characters. Ladyfinger has smaller kernels than does Tom Thumb and they are a straw-yellow rather than a butter yellow. The ear of Ladyfinger does indeed suggest a finger, being slender and straight-sided, while the ear of Tom Thumb, though usually even shorter, tapers from the center to both ends, like a miniature barrel. In growth habit the two varieties are diametrically different. Tom Thumb is the earliest of early varieties and does not grow into a normal plant south of the northernmost tier of states. In most of its characters it is a typical northern flint (Brown and Anderson, 1947). It has one or two ears on the main stalk when grown in southern Minnesota. It tillers readily and the tillers are inferior to the main stalk. The foliage is a yellowish-green and the tassel has few and slender branches. Ladyfinger is the latest variety of any kind of maize in most of the gardens in which it grows. Its growth habit is like that of Oriental Popcorns (Stonor and Anderson, 1949): it develops slowly; its leaves are upright; the internodes are short; it may have -5 to 7 ears on the main stalk. It tillers abundantly and the tillers are subequal to the main stalk in size and appearance (pl. 12, fig. A). The tassel, though small, has many branches and is scarcely exserted from the upper leaves.

The kernels of an ear of maize are usually set in longitudinal rows of from 8 to 30 or more. Certain genetic stocks, and an occasional ear in open-pollinated varieties, may have only 4 rows. For numbers much above 30, the kernels are so crowded that the rowing is obscure; various irregularities may modify or conceal the row pattern (Weatherwax, 1916, 1917), but in most of the varieties of Zea Mays the kernels over a good portion of the ear are arranged in definite and usually conspicuous rows. In nearly all varieties the row number is even, since the kernels arise from paired spikelets which are themselves disposed in regular rows (Collins, 1919). The history of row number is apparently complex. Both in South America and in the southwestern United States archaeological investigation has demonstrated that the earliest varieties had 12 or 14 rows (Bird and Anderson, in press), and Bird's recent excavations indicate that this condition persisted unchanged for a long period. Both in South America and in the southwest 8and 10-rowed varieties appeared at a later date (Carter and Anderson, 1945). Another type of change in row number has been associated with the dent corns of Mexico. Since at least the times of the Toltecs, row numbers of 16 and above have been characteristic of central Mexico (Anderson, 1946), and it is apparently chiefly from that center that they have been so widely spread around the world as to characterize many of the world's centers of commercial corn production. Since the early days of studies upon inheritance in Zea Mays (Emerson and East, 1913) it has been apparent that the genetic basis for differences in row number is complex. Extensive and careful studies were carried on by the late R. A. Emerson and his students and collaborators for several decades. While he made a number of preliminary and informal reports his results in different crosses were rather contradictory and have not yet been formally published. Lindstrom (1929, 1931) observed linkage between genes for row number and genes for pericarp color. The morphological bases for differences in row number are difficult to study upon the ear itself, an organ so modified that its exact relation to other grass inflorescences is still a subject for research and so highly vascularized that such research is technically difficult. Accordingly, for the past decade, we have carried on a comprehensive survey of variation in both the ear and the tassel (the male and female inflorescences). As Bonnett's (1940) developmental studies have clearly shown, these two inflorescences are scarcely distinguishable morphologically in their early stages but beyond a certain point the ear becomes progressively harder and thicker, the tassel progressively more lax and expanded. From modern

The homologies of tassel and ear structure in maize, and the problem of the morphological relationship between the inflorescences of maize and other genera in the Gramineae, have provided a fascinating study for many workers. Mangelsdorf (1945) has lately compiled a critical review of the earlier contributions to these problems, and with the aid of more recent data has endeavored to formulate a hypothesis incorporating the main features of previous theories. It is interesting to note that most workers have considered the maize inflorescence (tassel or ear) as a unit for comparative study which is complete in itself. Anderson (1944) first realized the importance of considering the structure of the inflorescence as a culmination of developmental processes which are common to the plant as a whole. It would seem that a study of the inflorescence apart from the rest of the shoot might neglect a very valuable source of information, and that a better understanding of the general developmental plan in the maize plant might furnish a new line of attack in interpreting the particular morphology of the inflorescence. Adopting this line of approach, the problem of ear and tassel homologies involves three ontogenetic questions: (1) Bonnett (1940) showed that the primordia giving rise to lateral branches, and the primordia giving rise to paired spikelets on the main axis of the tassel, are homologous structures. Paired spikelets may therefore be regarded as greatly reduced lateral branches. Is this reduction peculiar to the tassel or is it the culmination of a process initiated during the vegetative phase? (2) Mangelsdorf (1945) concluded that the ear of maize as exemplified by the female inflorescence of Guarany pod corn is "fundamentally identical with the spikes of certain other species of grasses .... and like many of them is probably derived from a panicle as the result of reduction of branches. There is not the slightest evidence of fusion." Without in any way disagreeing with the first part of this statement, it may be pointed out that from the developmental point of view the morphology of the panicle represents the crux of the problem; namely, by what developmental process is the simple alternate (distichous) arrangement of primordia, as seen in the basal vegetative portion of the shoot, transformed into the polystichous arrangement found in the apical reproductive region. (3) Bonnett's developmental studies have shown that the florets of both male and female inflorescences are potentially hermaphrodite. What factors determine

In classifying the different varieties of Indian corn, Zea Mays, scientists have paid little attention to comparative floral morphology. Since the kernel is economically the most important part of the maize plant nearly all classifications have been based on its texture and morphology. The most recent classification is that of Sturtevant (1899), which is based on the characteristics of kernel texture and the development of husks around individual kernels. We may summarize Sturtevant's classification as follows: Zea tunicata, the pod corns: "each kernel is inclosed in a pod or husks." Zea everta, the pop corns: "characterized by the excessive proportion of the corneous endosperm and the small size of the kernels and ear." Zea indurata, the flint corns: "readily recognized by the occurrence of a starchy endosperm inclosed in a corneous endosperm." Zea indentata, the dent corns: "recognized by the presence of corneous endosperm at the sides of the kernel, the starchy endosperm extending to the summit." Zea amylacea, the soft corns (the flour corns): "recognized by the absence of corneous endosperm." Zea saccharata, the sweet corns: "a well-defined species group characterized by the translucent, horny appearance of the kernels and their more or less crinkled, wrinkled, or shriveled condition." As Anderson and Cutler (1942) have pointed out, this classification is an artificial one and is of aid only in cataloguing different varieties. It does not indicate relationships between different groups or varieties. Details of floral morphology are among the most important characters in the taxonomy of grasses. Although all the maize varieties, as far as we know, belong to one botanical species, investigations made thus far have shown that comparative morphological studies of reproductive organs can be of great importance. During their long existence many of the varieties of maize have become fairly constant. In some cases the morphological differences between different strains of maize are like those between closely related species of wild grasses. Not only does the study of the spikelets of the tassel give us a new character for understanding the natural classification of the present-day varieties of maize, but it may also give important clues to the origin of these varieties. During the

There is a basic pattern for most grasses and this pattern is repeated throughout each plant, in reproductive as well as vegetative parts. The main axis of the maize plant bears leaves and buds on opposite sides of successive nodes. This pattern extends to the branches, the tassel, and to the ear. In the maize tassel and ear the parts and even their arrangement may be modified, but the basic arrangement is still that of the stem of any grass. This can be seen easily in the lateral branches of the tassel and in ears with only four rows of grain. All parts of the maize plant are made up of similar units. The name "phytomer" has been applied to these (see Esau, 1943, for a discussion of this as applied to the stem). A phytomer consists of an axillary bud at its lower end, a section of the stem (the internode), and is terminated by a leaf. It corresponds to Collins' (1919) alicole, although his original definition included only the spikelet or pair of spikelets and not the associated portion of cob or stem. Because the maize pattern is repeated throughout the plant we can expect almost any change in one part to be repeated in homologous parts. For example, when hairs on the leaf sheath are large and numerous, there will be large and numerous hairs on the glumes of tassel and ear. Because of this repetition of plant pattern, some organs which are not strictly homologues will reflect changes in other parts. Thus, in one race of Bolivian maize, when the tassel branches and the rows of spikelets on the central spike are nearly doubled in number, the number of rows of grains on the ear and vascular strands in the stem are correspondingly increased. The extent of variation in the grasses is greatest in the flowering parts and least in the vegetative areas of the plant. Thus the leaves are still arranged dichotomously in the Bolivian maize even though the number of tassel branches and rows of grains has been doubled.

Plants containing each one of seven different tassel-modifying genes were treated with Gibberellic Acid-distilled water mixtures every three days throughout the growing season until tassel emergence. GA was found to suppress expression of ramosa-1 (rai). Tassel-seeds 2 (ts2), 5 (Ts5) and 6 (Ts6), Tunicate (Tu) and Vestigial glume (Vg) were all modified, but not so much that they could not be recognized. The recessive male-sterile 1 (msi) remained male-sterile. An explanation of certain elongation patterns in these plants is tentatively made, which points toward the idea that GA depends at least in part on the presence of auxin (IAA) for its effects. NORTON H. NICKERSON, Missouri Botanical Garden, 2315 Tower Grove Ave., St. Louis 10, Missouri.

The exact correspondence between the variation of the male and female inflorescence of Zea Mays is a problem which has attracted a number of minds and has produced several theories, none of which completely satisfied the existing data. The morphological facts have been assembled by Weatherwax ('23, '35), and he, Collins ('19) and Kempton ('19) have reviewed the pertinent literature. After surveying all the existing evidence Collins' final conclusion was that, though he had used the hypothesis of a shortened and twisted central spike to explain the results in crosses between Zea and Euchlaena, "'facts of other kinds are more easily interpreted by the theories -of fasciation and reduction of branches . . . . There are also facts that do not seem to accord with any of the theories yet proposed. Until the apparently contradictory evidence can be reconciled, it seems best to keep the several possibilities in mind and await additional evidence before attempting a complete interpretation." Though the facts reported below shed further light on the problem, Collins' words of caution are still in order and the complete solution, while perhaps not far distant, is still to be awaited. Though he disagreed rather completely with Collins on other points, Weatherwax's final conclusions ('23) concerning the ear were very similar. "The last word has not yet been said on the evolution of the ear of corn, and it cannot be said until further researches have corrected, amplified, and evaluated the data now at hand, and woven the results into a harmonious theory." [loc. cit. pp. 112-113]. Earlier workers were interested in the problem of ear and tassel relationships chiefly from theoretical considerations. With the development of large-scale scientific maize breeding in the U. S. cornbelt, itis now a problem of considerable economic importance as well. If a corn breeder could size up the potentialities of the ear, merely by examining the tassel, he could take many short cuts, both in the creation of new inbred lines and in maintaining their desirable characters.

Zea Mays L., one of the most highly evolved of all grasses, is still botanically much of an enigma. Commonly known as Indian corn or maize, it was a very important plant to the peoples of the New World long before the arrival of Columbus. It formed the basis of the highly developed Inca, Maya, and Aztec civilizations and was the staple crop from Canada to Chile for several thousand years. It is, of course, quite important to the present-day inhabitants of Central and South America, and agriculture and industry in the United States uses three and one-quarter billion bushels annually. Botanists have until recently followed almost exclusively Sturtevant's (1899) classification of contemporary races of maize by kernel types. Although this classification is an artificial one, it has proven to be of practical commercial worth. Archaeologists have long known the value of maize kernels found at excavation sites for determining types of maize grown and the uses to which they were put. Until the last few years, other parts of the maize plant have been quite generally neglected as a source of historical data, chiefly because of the complexities involved in determining and evaluating such evidence as they contain. Evidence from maize tassels has been used with promising results (Alava, 1952; Anderson, 1944Ab, 1944c, 1949a, 1951; Anderson and Brown, 1948; Anderson and Cutler, 1942; Brown et al, 1952; Cutler, 1946; Wellhausen et at, 1951, 1952). Prat (1948) showed that in maize and other grasses hairs and other epidermal emergences can be used as a basis for identification and classification. Internode patterns have been studied by several workers (Anderson, 1943, 1949a; Anderson and Brown, 1948; Anderson and Schregardus, 1944; Stonor and Anderson, 1949; Wellhausen et al, 1951, 1952). Ear and tassel ontogeny have been studied by Bonnett (1940, 1948) and Kiesselbach (1949). Esau studied the ontogeny of the maize vascular bundle. Surprisingly little has been done to measure and evaluate those morphological structures which are present on a maize cob after the kernels have been removed. Weatherwax, a pioneer in the study of the maize cob, pointed out (1918) the need and value of accurate morphology in understanding this structure, and demonstrated (1920) the orderly spikelet behavior underlying changes in kernel rowing. Fujita (1939) observed that an even number of pairs of kernels resulted in straight rows, and an odd number in spiral rows. Cutler (unpublished work) made many histological studies of the cobs of both North and South American maize, as well as of several closely related genera. Lenz (1948) indicated the types