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1. The nodules and root tissues of four species of Indian legumes, Cicer arietinum (gram), Pisum sativum (pea), Lens esculenta (lentil), and Lathyrus sativus, grown on molecular and/or combined nitrogen, were analyzed for ninhydrinreacting substances by paper chromatography. 2. Seventeen known amino acids and five unknown substances were detected in the tissues, only one of which was unique for the nodules. This was an unidentified substance with a high mobility with phenol-water but very low mobility with benzyl alcohol-acetic acid-water. 3. The bearing of the amino acids on the fixation process has been discussed. The products of fixation and assimilation of inorganic nitrogen have been found to be essentially similar except for the occurrence of certain unidentified substances in the roots and nodules of plants utilizing both forms of nitrogen.

Glycogen was extracted from glycogen bodies of 19-day chick embryos with KOH and absolute alcohol, and hydrolyzed in H2SO4. The hydrolysate was analyzed for carbohydrates by means of paper chromatography, using known carbohydrates as controls. Special techniques are described which were employed in the preparation of the hydrolysate and for chromatography. The carbohydrate of the glycogen body was identified as glucose. Evidence is presented to suggest that the polysaccharide stored by the glycogen body of 19-day chick embryos consists of glucose and not other carbohydrates.

Ethanolic extracts of spore masses from colonies of two isolants of Race 1, three isolants of Race 2, and one isolant from each of Races 3 and 4 grown on either a corn-meal or a bean agar were analyzed by two dimensional paper chromatography. Thirty-five ninhydrin-positive compounds were detected; fourteen were identified as known amino acids or related compounds. Attempts to distinguish isolants with respect to race on the basis of unique compounds or an array of compounds were unsuccessful.

1. American paper products contain an extractable, heat-stable lipid (PF) with high juvenile hormone activity for the bug, Pyrrhocoris apterus. When reared in contact with "active paper" or extracts prepared front active paper, larval Pyrrhocoris undergo one or more supernumerary larval moults and finally die without completing metamorphosis or attaining sexual maturity.2. As a potent analogue of the juvenile hormone of Pyrrhocoris, PF blocks those aspects of development which can take only in the absence of juvenile hormone—namely, the transformation of the fifth stage larva into an adult. By contrast, it fails to interfere in any way with normal growth and moulting during the first four larval instars—i.e., with developmental events which normally take place in the presence of high levels of endogenous juvenile hormone.3. Sensitivity to PF is maximal at the outset of the final (fifth) larval instar. At this particular stage, metamorphosis is blocked by contact with PF for a period as brief as one hour. ...

s of Papers Presented at the Marine Biological Laboratory : Abstracts of Seminar Papers, 5 July 1960.-- 1 page

Paper chromatograms of flower extracts exhibited 44 compounds: 9 were seen by visible light, 19 by UV, and 16 by UV using ammonia fumes. The interspecific hybrids yielded compounds not found in either the parental species or the genus; compounds found in the species did not occur in extracts from the interspecific hybrids. Although chromatographic patterns could be used to characterize each species, the patterns did not provide meaningful clues to their relationship. Chromatograms from interspecific hybrids did not indicate the parentage of the hybrids.

A paper chromatographic analysis of ten species of Tradescantia was made to determine if biochemical methods could be used to detect specific differences among the species and possible pathways of speciation. Two-dimensional chromatograms of extracts from roots, leaves, and flowers were examined, using ninhydrin and ultraviolet light. Ninhydrin-positive spots exhibited mostly quantitative differences. Ultraviolet-fluorescing spots from the three extracts yielded different patterns. The virginiana complex, encompassing seven of the ten species, could not be separated without accepting a one- or two-spot difference as being conclusive. The other three species could be separated with less difficulty. The relationships of the North American species, as determined by other workers, were supported by the results of this study.

1. A paper chromatographic analysis of root extracts from individuals with different genotypes for flower color in Collinsia heterophylla and C. tinctoria, from small populations belonging to an additional thirteen species in the genus, and from small populations of six interspecific hybrids or their progeny yielded a total of thirteen "spots" detected by ultraviolet light. 2. Chromatograms did not provide an acceptable basis for separating taxa or for clarifying the status or relation of taxa.

When reared in the Biological Laboratories at Harvard University, the European bug, Pyrrhocoris apterus L., failed to undergo normal metamorphosis. In the initial cultures, 1,215 individuals showed normal growth and moulting until the fifth larval instar. Then, instead of metamorphosing into adults, all except one individual underwent a supernumerary larval moult to form “?�perfect” sixth instar larvae or adultoid sixth instar larvae (Table I ) . All the perfect sixth instar larvae underwent yet another supernumerary moult to form even larger seventh instar larvae or seventh instar adultoid larvae. Of the entire group of 1,215 larvae, only one individual completed metamorphosis and attained sexual maturity. Among tens of thousands of Pyrrhocoris which one of us (K. S.) had cultured in Prague, the spontaneous formation of a sixth instar had never been encountered. Metamorphosis had always taken place at the end of the fifth larval stage—a result directly attributable to the inactivation of the corpora allata and the cessation of juvenile hormone secretion at the outset of the fifth instar (SlAima, 1962) . The formation of sixth stage larvae had been provoked only in experiments in which juvenile hormone was supplied by the implantation of active corpora allata (Novak and SlAima, 1961 ; SlAima, 1964a) . For these several reasons, it seemed certain that the Harvard cultures of Pyrrhocoris had access to some unknown source of juvenile hormone. One possibility was that some feature of the Harvard environment served to prevent the normal inactivation of the animal's own corpora ailata and that, in this indirect manner, metamorphosis was blocked by the prolonged and abnormal secretion of juvenile hormone. An alternative possibility was that the Harvard cultures were under the influence of an environmental factor which, in itself, possessed juvenile hormone activity. The present study initiates a detailed investigation of the phenomenon.

A LL the hills in the immediate vicinity of Porto Alegre appear to be formed of granite or porphyry, but I had no opportunity to note the geological features closely. The strips of woodland which remain are less matted than the forests of Rio de Janeiro, and there are fewer vines and palm-trees; ferns are abundant, and we collected a score of species. One of the commonest birds here was a brown species allied to the thrushes, and called, *7oao de barro-literally, clay-John. It owes this name to its singular nest, which is composed entirely of clay, and roofed over above; it is frequently placed in the most exposed situations, such as the tops of fence-posts, or the dead branches of trees. They are very tame, and I have frequently watched a pair of them at work. They bring the material, soft, unctuous clay, in good sized lum1ps, which they obtain near some water-course; these lumps, previously well kneaded, are laid first on the post or branch on which the nest is to be built, so as to form a foundation; each portion is well packed in with the bill, which is subsequently used like a trowel to smooth the surface. The sides are built up in the same way, the two birds working incessantly for several days; they seem to prefer rainy or foggy weather, when the wet clay can readily be found, and when the building is not hindered by the too rapid drying of the parts which are already finished. The nest, when completed, is nearly globular, seven or eight inches in diameter, and with walls an inch and a half thick; the cavity may be compared to a mold of a very crooked squash, the larger end forming the nest, and the smaller, turned downwards, the entrance. The clay soon becomes nearly as hard as brick, and the nests may last for many years, though I do not know that the birds use them more than once. In Rio Grande I found the birds breeding in June; three dirty white eggs a~re laid. This, or a closely allied species is found throughout Southern and Central Brazil. A gallinaceous bird called perdiz (partridge) was also common on the grassy hillsides. Its plumage, prettily mottled with brown, is one of the best examples of protective coloration that I have

The nuclear conditions during the life-history of Cutleria multifida and Aglaozonia reptans may be summarized as follows: 1. The nucleus of both male and female plants of Cutleria multifida contains 24 chromosomes; and the male and female gametes produced contain the same number. 2. In the union of gametes the number is doubled, and 48 chromosomes appear in the sporelings, which develop into the Aglaozonia form of Cutleria. Therefore it is evident that the individual bearing the name of Cutleria multifida represents the gametophytic phase of the species, 24 being the gametophytic number of chromosomes; and the Aglaozonia form of Cutleria represents the sporophytic phase of the species, 48 being the sporophytic number. 3. Aglaozonia reptans contains 48 chromosomes, and the number is reduced in zoospore formation, the zoospore containing 24 chromosomes. The zoospore with the reduced number of chromosomes germinates without conjugation. Although the nuclear details of the sporelings of Aglaozonia reptans hav...

The spindle bridges of Abraxas spermatocytes do not appear to have any relationship with the de novo formation of Golgi bodies. No hemispherical nucleoli analogous with the heterochromosomes of other insects have yet been found in Abraxas. The Golgi bodies are present in the smallest spermatogonial rosettes in which the newlyformed spindle bridges are unrelated to the nuclei; in such cells the nucleoli have no connection with the spindle bridges. The spindle bridges, as has been generally concluded, are a means whereby sister cells in a nest are kept at the same state of nutrition. Spermatocytes very badly infected with bacteria, keep step with non-infected sister cells, this, it is concluded, by virtue of the spindle bridges. Radiated testes show nests with dying and apparently undamaged cells side by side. This type of injury appears to be something different from mere inadequacy of nutrition, such as the presence of large numbers of bacteria could bring about.

ALTHOUGH scattered observations on the life span of many vertebrates and invertebrates are legion, the accurately Collected mortality. data necessary for the construction of a life table are, apart from mnan, few indeed. For the insect group, life tables in complete or abridged form have been published for representatives of four orders: the Orthoptera (Blatta orientalis), the Lepidoptera (Telea polyphtemis and Acrobasis caryae), the Diptera (Drosophtila melanogaster and various of its mutants), and the Coleoptera (Tribolit am1 coonfusumt). Reference to the first three orders will be found in the papers of Pearl and AMiner (1935 and 1936); to the last order in Pearl, Park alcd Mliner (1941). The present paper reports a life table for another, and hitherto little studied, flour beetle, Tribolimi qnadens. The details of life table construction, the significance of the life table for many pleases of population biology and a review of the literature dealing with mortality in infra-human populations are not considered pertinent for this short paper. If interested, the reader can find further information in Bodeniheinier (1938), Dublin. and Lotka (1936) and Pearl (1940). The flour beetles (Tribooliulml cojifusutm and Triboliamn;^ castaneum) are proving to be appropriate organisms for experimental populations studies (see Ford, 1937, and Park, 1941). It is hoped that, as more backg-round data 1 I wish to express my sincere thanks to Dr. Alfred J; Lotka, of the Metropolitail Life Insurance Compally, whose advice has been inv-aluable. I am also greatly iiidebted to Mr. Albert W. Buzicky, of The University of Miimesota, for furnishilgg me with a culture of Triboltm macdens as well as for a ilnunber of suggestions. This investigation has beeni aided by a grailt from the Dr. Wallace C. adll Clara A. Abbott Meioriml Funid of the University of Chicago.

1. The isoelectric point of pericardial organ cardio-excitor material, determined by paper electrophoresis, is near pH 3.2. Paper chromatography demonstrates two active compounds in pericardial organ extracts which stain with ninhydrin and upon acid hydrolysis are identified as peptides. These peptides differ in composition by only a small number of residues.3. The peptides contain proportionally more glutaminyl residues than positively charged residue (lysine or arginine), one other negatively charged residue, and a small number of neutral amino acids.

Introduction NIELSEN and HARTELIUS (2) succeeded in forming substance B by chemical means. Their first results were obtained by autoclaving the "Rhizopus-nutrientsolution" in the presence of filter paper and assaying by dry weight yields of Aspergillus niger. They also showed that the mineral salts played no part, while the important factors were the nitrogen source, the carbon source, and the filter paper. Various nitrogen sources were tried, and the results indicated that all organic ammonium salts were effective, that NH4Cl had no effect, and that NaNO3 produced an inhibiting factor. Tests with various carbon sources showed that all were more or less effective. Six different filter papers were tried, and Schleicher and Schull no. 597 proved to be the most effective. They also state that the ash of the filter paper gave results similar to those of the filter paper itself. This synthesized substance not only functioned similarly to substance B of the Rhizopus filtrate, but also-like the latter-it was soluble in water, insoluble in ether, and stable to oxidation by perhydrol. In a subsequent paper (3), these workers demonstrated the production of this active substance by autoclaving 2 per cent lactic acid and 2 per cent glucose, at

D URING the spring and summer of 1931, investigations were undertaken on the effects of extreme temperatures on highly desiccated cysts.2 Filter paper on which Colpoda cucullus had been induced to encyst was exposed to room humidity and temperature for several weeks and then cut into small rectangles. These rectangular pieces were carefully rolled, and to each piece was clamped a U-shaped segment of soft iron wire. Thereupon they were subjected for several days to high vacuum (about io-5 mm. Hg) by means of a mercury pump which was provided with a liquid-air trap and an ionization gauge. Small pyrex tubes were sealed alternately to either side of a large extension tube on the high vacuum side of the mercury pump and kept at high temperature (450 C.) during the 2 or 3 days of evacuation. Into these small tubes, after cooling, the rolled pieces of filter paper were introduced with the aid of a magnet. The tubes were then sealed off. Fifty-three such tubes which had been tested for high vacuum by means of an induction coil were placed from time to time into liquid air for periods from i hour to I21 days. After exposure, the tubes were broken and the small clamps were removed from the filter paper. These pieces of filter paper were thereupon immersed in balanced medium; and, with no exceptions, free-swimming Colpoda were observed in the medium in the course of several hours. Controls, of dishes and medium, were negative.

Although this paper finally treats of measures for the extermi nation of ants, the experiments 1 herein recorded were begun with a view to ascertaining the temperature preferred by ants and con ducing to their rapid development in artificial nests. The ants employed were Lasius lalz@es, yellow, translucent ants, from four to five millimeters long; Stenamma fulvum, brown ants, from six to seven millimeters long; Camponotus pennsyl vanicus, black ants with dense integument, from eight to eigh teen millimeters long. The ants were chosen with reference to color and size, a colony of Camponotus whose members varied exceedingly in stature having been previously captured. A special nest was made, affording opportunity for the ants to choose temperature agreeable to them. It consisted of a copper2 half-cylinder, three centimeters in diameter, in which the central portion of the interior, one meter or forty inches in length, was partitioned from the further extending ends, lined with white blotting paper apart from the copper, and imbedded, concave side upward, in cotton wadding which extended slightly over the edges of the half-cylinder at its sides. The half-cylinder was made level, so that gravity should not influence the behavior of the ants. The central portion was kept dry throughout, that the influence of humidity might be eliminated. It was covered with glass microscope-slides laid transversely, and topped with blotting paper so as to secure uniform darkness within. The layer of wadding between the edge of the copper and the glass roofing admitted sufficient air for the ants to breathe, and left no interstice for their exit. At the right-hand end the bare copper extended beyond the supporting table and was heated by an alcohol flame. At the

THE matter contained in the short paper now presented has, with the exception of a few necessary references to the results of other scientific investigations, been acquired by personal observation and experimentation over a period of more than ten years. It has been written with a view towards presenting some of the more interesting discoveries which have resulted from the writer's investigations into the habits of young postlarval lobsters, their rate of growth, and various other facts concerning lobster culture in general. The life-history of the lobster has been studied for many years both in Canada and in the United States as well as in Europe. One of the earliest accounts is that by Professor Sydney I. Smith (1) in the Anterican Jorncal of Science and Arts, vol. 3, for the year 1872. In this article the author states that there are three stages in the life-history of the American lobster (Homacrs amiericanas) which bear little or no resemblance to the adult and one stage which closely resembles the adult. George Ossiamn Sars, professor in the University of Christiania, Norway, in 1874, published a paper which contains a figure of the first stage of the lobster. A few years later, in 1895, Professor Herrick, of Adelbert College, U. S. A., published a most exhaustive and beautifully illustrated work on the American lobster. In the United States experiments in lobster culture have been carried on for many years. In the federal hatcheries at Woods Hole, Massachusetts, and Boothbav Harbor, Maine, no work of this nature is now being done. The former was closed in 1912 and the latter in 1919 after having produced 7,500,000 fry in that year. Likewise in 160

(WITH SIX FIGURES) The purpose of this paper is to call attention to the fact that long continued use of certain nutrient solutions, commonly considered complete, may produce injurious effects which can be removed by the addition of traces of elements ordinarily considered unessential for plant growth. Students of plant nutrition who have employed cereals may have failed to encounter this difficulty, because the seeds, or the inevitable impurities of the chemicals, or the solubility of the containers have supplied the quantities of these elements necessary for short periods. Investigators in this field of experimentation have frequently ascribed the deleterious action of solutions to the toxicity of the distilled water employed. As will subsequently be shown, the deleterious action of the nutrient solutions used in this experiment was not due to traces of the heavy metals, or to volatile organic compounds, because all water was carefully treated with carbon-black, a powerful absorbing agent. In the course of experiments on the effects of salts upon the growth and composition of orange trees, it was found that a characteristic type of injury usually appeared after i8-24 months. There is no evidence that the bad results were due to an accumulation of materials in the sand cultures, because the containers were well drained and the cultures were brought to their optimum moisture content with distilled water before the first addition of the nutrient solution. As each later supply of nutrient solution percolated downward through the sand, it displaced practically an equal volume of the old solution. Moreover, the harmful effects on the trees were overcome, not by the use of materials of greater purity, but by the addition of something previously omitted.

1. The phycobilin chromoproteins of three species of Porphyra have been separated by column chromatography and their individual absorption spectra recorded. These "chromatographically purified" chromoproteins were subjected to acid hydrolysis and their constituent amino acids resolved by paper chromatography and determined quantitatively by a densitometric method.2. The quantitative amino acid composition of each chromoprotein differed. The dicarboxylic amino acids alanine, glycine and the two leucines were most abundant. Alanine was found to be present in high concentration in the phycoerythrin of P. naiadum and P. perforata.

1. Avena seedlings were grown in darkness at 25⚬ C. on moist filter paper in preparation dishes. When the coleoptiles were 1.5, 4, 10, 17, and 36 mm. in length, they were uniformly sectioned at 125 or 250 μ on a rotary microtome. Peptidase determinations were made on these segments, and their reduced weights were obtained by use of the gradient tube. Cell counts were made for successive 125-μ segments of coleoptiles 4 and 10 mm. in length. On a per segment basis, peptidase activity, reduced weight, and cell number were found to decrease in progressively older coleoptiles. 2. For any given coleoptile 4 mm. or more in length, enzyme activity per unit weight of tissue, or per cell, was consistently greater at the tip. Correlations between morphological structure and auxin and peptidase gradients in the coleoptile are pointed out.

PAPER electrophoresis has stimulated the investigation of proteins in inp vertebrate biological systems that were formerly considered too minute for analysis. The preliminary phases of these investigations are exploratory, and the emphasis has thus far been placed upon the number of fractions detectable and their mobility within a given system. Reports of from two to six protein blood fractions have been made for vari