Imágenes de páginas

lieved from these results that the vitamin in question will be found universally distributed in plant and animal tissues, and that it plays an essential part in the respiratory process. The evidence favors the view that this vitamin is the watersoluble antineuritic B.

The preparation of a stable vitamine product and its value in nutrition: H. E. DUBIN. An active stable vitamine product has been prepared from corn, autolyzed yeast, and orange juice. This vitamine product, containing the antineuritic, antiscorbutic and antirachitic vitamines, has been given the name "Vitaphos." A tentative analysis shows 10 per cent. calcium oxide, 15 per cent. phosphorus (mostly organic), 3 per cent. nitrogen, and 2 per cent. fat. Experiments with pigeons, guinea pigs and finally with children receiving "Vitaphos'' in the diet, gave results showing that the product possessed marked growth promoting properties and both preventive and curative properties as regards polyneuritis and scurvy. Cases of rickets treated with "Vitaphos" showed marked improvements and considerable gain in weight. Further experimentation is under way.

Chemical isolation of vitamines: C. N. MYERS AND CARL VOEGTLIN. Brief historical discussion of previous chemical work with special reference to the pioneer researches of Casimir Funk. Vitamines are classified as antineuritic, antirachitic and antiscorbutic. Autolyzed yeast filtrate was used in part of the experiments but was found unsatisfactory on account of its complexity. Mastic emulsion, Lloyd's reagent, and ferric chloride were used in removing the active material from the filtrate. These purified fractions were tested for activity on polyneuritic birds. Dried yeast was finally used as the source of active material. Purification by means of heavy metal precipitation was carried out yielding a crystalline substance. The vitamine content of wheat flour: C. O. JOHNS, A. J. FINKS AND M. S. PAUL.

The relation of plant carotinoids to growth, fecundity and reproduction in fowls: LEROY S. PALMER AND HARRY L. KEMPSTER. White Leghorn chicks were raised from hatching to maturity on rations containing the merest traces, if not entirely devoid, of carotinoids.

The full grown

hens exhibited normal fecundity although the yolks of the eggs were devoid of carotinoids. The carotinoid-free eggs showed normal fertility. Α second generation of chicks, free from carotinoids at hatching have been hatched from the carotinoid

free eggs.
Carotinoid-free egg yolks contain a
residual yellow pigment readily extracted by ace-
tone, which is not related to the normal axantho-
phyll of the yolk. This paper appeared in full in
the September issue of the Journal of Biological

The physiological relation between fecundity and the natural yellow pigmentation of certain breeds of fowls: LEROY S. PALMER AND HARRY L. KEMPSTER. (By title.) The fading of the yellow color from the ear lobes, beak, shanks, etc., of a hen during fecundity is due to the fact that fecundity deflects the normal path of excretion of xanthophyll from these parts of the skin to the egg yolk, with the resulting gradual disappearance of pigment from the epidermis because of natural physiological changes in the structure of the skin. It is impossible to restore xanthophyll to the epidermis or to color the adipose tissue of hens as long as fecundity exists. The loss of pigment from the ear lobes, beak, shanks, etc., as the result of egg laying, is an index of continuous fecundity only, not of heavy egg laying. This paper appeared in full in the September issue of the Journal of Biological Chemistry.

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The influence of specific feeds and certain pigments on the color of the egg yolk and body fat of fowls: LEROY S. PALMER AND HARRY L. KEMPSTER. (By title.) Carotin and annatto are without influence on the color of the visible skin parts and adipose tissue of poultry. Sudan III. colors only the adipose tissue of non-laying hens and is without effect on the visible skin parts. With laying hens the egg yolk is colored in addition to the adipose tissue. Xanthophyll readily colors both the adipose tissue and visible skin parts of fowls of the type of the White Leghorn breed, as long as fecundity does not exist. Yellow corn and green feed are rich in xanthophyll. Hemp seed, barley, gluten feed and red corn contain traces of xanthophyll, while wheat, wheat bran, oats, cottonseed meal, meat scrap and blood meal contain negligible quantities of the pigment. This paper appeared in full in the September issue of the Journal of Biological Chemistry.

The relation of the natural enzymes of butter to the production of "tallowiness" through the agency of copper salts: LEROY S. PALMER AND W. B. COMBS. (By title.) "Tallowy" butter was produced by the addition of 0.017 per cent. copper lactate to both raw cream and cream which had been pasteurized at 79°-80° C. In each of several experiments typical tallowiness and bleaching oc


curred in the raw cream butter several weeks before it appeared in the butter from the pasteurized The oxidizing enzymes in raw-cream butter apparently accelerate the catalytic activity of the metallic salts which cause the production of typical "tallowy" butter. It was found that over-neutralization of the cream failed to accelerate materially the production of tallowiness by copper lactate. This paper will appear shortly in the Journal of Dairy Science.

The nutritive value of commercial corn gluten: C. O. JOHNS, A. J. FINKS AND M. S. PAUL.

The effect of calcium on the composition of the eggs and carcase of the laying hen: G. DAVIS BUCKNER AND J. H. MARTIN. Authors have shown that limiting the calcium supply of laying hens to that naturally occurring in the foods fed, causes a progressive thinning of the shell yet it does not materially change the percentage composition of the egg shells or their contents. The continued laying of eggs under this condition causes a gradual depletion of calcium in the carcase of the hen. It would seem from the figures obtained that as long as the economy of the hens permitted a formation of an egg shell that the contents of the shell would remain constant, thereby permitting an average supply of calcium for the proper development of the embryo of the chick.

Protein requirement in the maintenance metabolism of man: H. C. SHERMAN. (By title.)

The development of Tribolium confusum Duval in certain foods: ROYAL N. CHAPMAN. This study has shown that the confused flour beetle, Tribolium confusum, grows at about the same rate in the different grades of wheat flour and in some of the so-called wheat flour substitutes, but in certain of the low grade wheat flours and in some of the "substitutes' metamorphosis is retarded. The rate of development in first middlings wheat flour was adopted as the control. The instars were plotted on the ordinate and the time in days on the abscissa in such a way that the curve of development would be a straight line bisecting the angle. When the curves of development in other foods were superimposed upon the controls they were found to be very similar except for a prolongation of the last larval instar. Since metamorphosis takes place during the last instar, this prolongation has been taken as a measure of the nutritive effect upon metamorphosis. Certain low grade wheat flours, rye flour and rice flour prolonged the last instar while corn flour, steel cut oats and a synthetic food prolonged all instars about equally.

The influence of quinine on uric acid excretion in man: H. B. LEWIS AND W. L. MCCLURE. (By title.)

The uric acid content of normal human saliva: H. B. LEWIS AND W. S. GRIFFITH. (By title.) Further studies on the chemical composition of normal and ataxic pigeon brains: MATHILDE L. KOCH AND OSCAR RIDDLE. A second series of analyses made on brains of pigeons affected with hereditary lack of control of the voluntary movements shows deviations from the normal brain in size and chemical composition. The brains are smaller. Eight analyses made on cerebrums and cerebellums show more pronounced changes in the cerebellums. Data for the chemical changes in the brain which accompany age have been obtained for a series of ages in the pigeon. The new and earlier evidence warrants the conclusion that chemical differentiation does not proceed as rapidly in the brain of ataxic birds as in the brains of normal birds.

A comparison of the distribution of various chemical groups in parts of the human and pigeon brain: OSCAR RIDDLE AND MATHILDE L. KOCH. Separate analyses made of anterior and posterior parts of the normal pigeon brain make it possible to compare these with similar parts of the human brain. It is found that the direction of the percentage differences in composition of the two parts of the brain is the reverse of that of the human in the case of every chemical fraction obtained. Also, from a chemical standpoint the cerebellum of the pigeon is an intermediate of the pigeon cerebrum and the human brain (cerebrum and cerebellum). The pigeon cerebrum is chemically least differentiated, the human cerebrum most differentiated, of the four organs compared.

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WHITMAN'S WORK ON THE EVOLUTION OF THE GROUP OF PIGEONS THE three volumes containing the work of Professor Charles Otis Whitman on pigeons published by the Carnegie Institution of Washington is a fine memorial to one of the leaders of zoological research in America. In the course of the sixteen years devoted to this work Whitman brought together birds from all parts of the world, bred them, studied their juvenile and adult plumages, and their habits, and made many crosses between different species. When he died in 1910, his extensive and valuable collection of living birds was saved through the devotion and sacrifices, both personal and financial, of Dr. Oscar Riddle, the editor of these posthumous volumes. After that first year of precarious existence, the Carnegie Institution met during the five years following the expenses of maintenance, and during this time the birds, under Dr. Riddle's care, were transferred to the laboratory at Cold Spring Harbor where Whitman's work is being carried forward. Without this support only a fragment of Whitman's results could have been preserved or the birds kept to complete many of the important problems that were at the time of Whitman's death still unfinished. The editing of the work has been admirably done by Dr. Riddle. It is a fortunate circumstance that what was left fell into the hands of one familiar with Whitman's ways of thinking, and thoroughly conversant with the many problems that had grown out of Whitman's studies; for "not more than one fifth of the matter" was in shape for publication when Whitman died.

Volume I. gives Whitman's views and his evidence for orthogenetic evolution. The editor says in the preface, Whitman "has accumulated the most weighty evidence for

1 Posthumous words of Charles Otis Whitman. The Carnegie Institution of Washington, 1919.

continuity as against discontinuity in the phenomena of variation, inheritance and evolution." And with this verdict his reviewer is not inclined to disagree, because as a careful study of Whitman's evidence and meaning shows, there is not much difference between what he understood by continuity and what is to-day called more often discontinuity.

In the introductory chapter from a manuscript written in 1909 that formed part of a lecture given at Clark University, the keynote to Whitman's antagonism to the mutation theory of de Vries is struck-a note that recurs throughout the first two volumes. Weismann, he says, taught us to look to germinal variation as the source of all variation that is hereditary. Then follows a paragraph that takes us to the heart of the matter: "Do we not have, then, in germinal variation, a better criterion of what is specific than we get in sudden appearance? Indeed, is it not here that the seeming suddenness of first appearance finds its explanation, and likewise the fact that so-called mutations involve the whole organism? If we are to accept the physiological conception of development, as is inevitable in my opinion, it is easy to see that a change, however slight, in the primordial constitution of the germ would tend to correlate itself with every part of the whole germ-system, so that the end stage of development would present a new facies and appear as a total modification, answering to what deVries would call a mutation. That some thing of this order does sometimes occur I have indubitable evidence, and in such form as to dispel the idea of discontinuity and sudden gaps in transformation."

With a slight shift of wording and emphasis the essential part of this statement is not very different from what we think to-day, for who will dispute now that a change (mutation) in the germ-plasm may affect many parts of the organism that develops out of such a changed germ-plasm? Such a view has not been found to dispel the idea of "discontinuity" of characters; on the contrary it is in full accord with it.

But the unit character is Whitman's bête noir. "The idea of unit-characters, however,

as distinct elements that can be removed or introduced bodily into the germ does not appeal to me as removing difficulties, but rather as hiding them; in short, as a return to the old pangenesis view of preformed characters. In this theory, as is well known, we have two miracles involved. The first consisted in a centripetal migration of preformed gemmules, and the second in the centrifugal distribution of the same elements. DeVries dismisses the first of these, but accepts the second, and on it rears the superstructure of his theory of mutable-immutable unit-characters. With all due respect to the distinguished author of this theory, and with abounding admiration for his great work and model methods, which have aroused universal interest and stimulated enormously experimental bionomics, I am strongly persuaded that his hypothesis of unit-character fails as a guide to the interpretation of the species and its characters."

"It is true a great amount of work on Mendelian heredity seems strongly to support the unit-character hypothesis, and that cytology offers some further support. Nevertheless, I have to confess a wholesale scepticism. The germ, as I believe and have long maintained, stands for an organized whole. It is a unit-organism, not an organism of units; all the features that arise in the course of development are within the sphere of the individual unity and integral parts of it, and whatever specificity they possess is completely determined and not of independent origin."

"The strongest suggestion of unit-characters is found in the phenomenon known as segregation. I do not understand the importance of this striking behavior of so-called alternative unit-characters. I am familiar with it and deeply interested; but I am unable to see in them the sum total of all we know about heredity. What I have said in regard to unit-character applies to the Mendelian doctrine. Mendelism, like mutation, neglects the natural history of the characters, it experiments with and is not primarily concerned to know how characters have originated and multiplied."

It may be that the emphasis laid on unitcharacter by some of the earlier enthusiastic followers of Mendel and the frequent confusion in their writings between the unit-character, so-called, and the change in the germplasm that gave rise to it, may justify Whitman's scepticism; but this charge can hardly be brought against de Vries, who stated over and over again that a single change in the germ-plasm may be the cause of manifold although slight changes in the characters throughout the whole organism.

In contrast to change by mutation Whitman opposes orthogenesis. Evidence for the latter he finds in his study of the group of pigeons. The evidence is the familiar argument from comparative anatomy and from the hypothesis of "recapitulation." Before Before taking up the evidence I can not refrain from quoting a fine and characteristic statement of Whitman's in the same lecture:

"I take exception here only to the implication that a definite variation-tendency must be considered teleological because it is not ' orderless.' I venture to assert that variation is sometimes orderly and at other times rather disorderly, and that the one is just as free from teleology as the other. In our aversion to the old teleology, so effectually banished from science by Darwin, we should not forget that the world is full of order, the organic no less than the inorganic. Indeed what is the whole development of an organism if not strictly and marvelously orderly? Is not every stage, from the primordial germ onward, and the whole sequence of stages, rigidly orthogenetic? If variations are deviations in the directions of the developmental processes what wonder is there if in some directions there is less resistance to variation than in others? What wonder if the

2 Whitman uses the word "recapitulation" in the sense for which the reviewer argued in 1903 ("Evolution and Adaptation," Chap. III.). As so used it means something essentially different from the word "recapitulation' " in the original sense of Darwin and Haeckel, unless the changes in the germ-plasm add stages only to the end of ontogeny as Whitman seems to think is the way in which the process takes place. (See a later footnote.)

organism is so balanced as to permit both unifarious and multifarious variations? If a developmental process may run on throughout life (e. g., the lifelong multiplication of the surface-pores of the lateral-line system in Amia) what wonder if we find a whole species gravitating slowly in one or a few directions? And if we find large groups of species all affected by a like variation, moving in the same direction, are we compelled to regard such a definite variation-tendency' as teleological, and hence out of the pale of science? If a designer sets limits to variation in order to reach a definite end, the direction of events is teleological; but if organization and the laws of development exclude some lines of variation and favor others there is certainly nothing supernatural in this, and nothing which is incompatible with natural selection. Natural selection may enter at any stage of orthogenetic variation, preserve and modify in various directions the results over which it may have had no previous control."

How far one is justified in extending the orderly sequence of embryonic development to the sequence shown in evolutionary advance is a large question and will no doubt be settled some day by fuller knowledge. At present our speculations must rest on the evidence at hand, and this evidence, Whitman finds, as stated, in his comparative studies of pigeon coloration, and in a most ingenious experiment of feather plucking.

His studies of domesticated breeds and their wild relatives led him to conclude that the blue wing with two black bars is not the original pattern as Darwin supposes, but rather the checkered wing covered with black spots. Both patterns are found to-day in wild birds, hence these birds can not be appealed to for a decision. But an examination of other species of pigeons shows that the checkered type is widespread and occurs in many varieties; and the young in many groups show a more checkered pattern than do the adults themselves. The Japanese turtle dove comes nearest, in Whitman's opinion, to the original type of wing pattern. The elaborate consideration that Whitman devotes to the subject indicates how important the question appeared to him;

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