THE WORLD POULTRY CONGRESS ALTHOUGH from a spectacular standpoint the recent Poultry Congress at Ottawa was an unqualified success, in consequence of which the poultry industry in Canada will derive considerable benefit, it is difficult at present to form an estimate of the educational value of the proceedings and to assess the importance of the information derived from the numerous papers and discussions. There would appear to be some justification for critical comment upon the fact that papers were not printed in advance, so that, as five sections were in session at the same time in different halls, delegates experienced great difficulty in gaining more than a vague impression of the whole, while the general public must await the publication of the official proceedings before it will be possible to summarize the educational effect of the congress.

The general impression, which is confirmed by the evidence of delegates, is that insufficient time was available to do justice to the many papers presented by authorities in the numerous branches of the industry. Not only did the "five-ring circus," as an American delegate described it, create confusion among those who were desirous of getting full educational value, but the absence of printed papers and the short time allowed for each paper necessarily limited the scope and the value of such discussion as was permitted. In view of the fact that the next congress is to be held in England in 1930 it will be necessary to formulate a policy that will do justice to the educational side, though it may be impossible to emulate the generous manner in which the Canadian government gave the poultry industry the best publicity it has ever enjoyed. The fortunate circumstance which enabled the Prince of Wales and Mr. Baldwin to visit the congress set the seal upon the efforts of the Canadian authorities to make the event a thorough success in the spectacular sense.

It is the more regrettable, therefore, that doubt exists as to whether the original purpose of world's poultry congresses was sufficiently considered. The International Association of Poultry Investigators

and Instructors inaugurated these triennial congresses with a view to enabling research workers and educationists to express their views and discuss experiences; and one suspects that interest in the Canadian congress spread so widely that the authorities found themselves with a plethora of good things which could only be embraced in the program by the quintuple-session plan. Even that would have been effective had the papers been printed in readiness for the proceedings, and it seems essential that that precaution should be taken at future congresses unless a drastic measure of compression is adopted by limiting the number of papers.

A further point which must be borne in mind for future congresses arises from apparent differences between investigators and practical poultrymen. It is conceivable that some of the former approach the task of research from the laboratory standpoint, whereas some practical men are so exacting as to demand that all investigation shall begin and end in the poultry yard. Doubtless there is a measure of reason on both sides, and a considerable amount of latitude must be allowed. It can not be denied, however, that research is a means to practical progress, and in connection with poultry-keeping its success must be measured by what it achieves in smoothing the path of the practical worker. That in turn depends upon close association and mutual confidence between the two classes, so that every effort should be made to interest scientific investigators in the every-day problems of the practical poultrymen at the same time as the latter are induced to take research workers into their confidence.-The London Times.

ONCE in a while some one writes a really new book such as "The Fitness of the Environment," "Winnie the Pooh," "Die Ausdehnungslehre" or "Oedipus Tyrannus." Sometimes such works are immediately approved like the first two; sometimes, as was the case with the third, not even the brightest minds of the time seem to appreciate the significance of the book and a generation or two elapses before the author comes into his own. With respect to the last, it was crowned at once with approval but perhaps not understood until the advent of psychoanalysis millenniums later, although to one who knows his Greek drama not quite so poorly as his psychoanalysis it sometimes seems as though the complex that afflicted Oedipus was the opposite of the Oedipus complex! Lotka's "Physical Biology" is a new, not merely a

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recent, book; whether it will go promptly with our effective scientific literature may be doubted; it is not easily read by most biologists who, rather than mathematicians or physicists, must make it effective. Like many really new works it contains a great deal of the author's thinking and writing for a good many years. The fundamental idea is simple, namely, that the rates of change of certain variables x1, In are functions of the variables themselves and of certain parameters P1, P2, . . . Pm, that there will be an equilibrium situation (with respect to the time) for those values of the variables which make the rates of change zero, albeit this equilibrium situation may change with changing values of the parameters, and that if the variables differ only slightly from their equilibrium values there will occur a variation of those variables in time. Primarily it is the study of this well-known system of equations that concerns the author and the interpretation of the results when the variables and parameters represent quantities of biological significance.

that it is fundamentally mathematical rather than physical biology, that it portrays the workings of a mind more mathematical than physical. Certainly physical biology should include a great deal about the theory of dimensions, about surface tension, etc., indeed much of the point of view and of the sort of material which may be found in d'Arcy Thompson's "Growth and Form." There seems to be in the book almost none of the sort of thinking that a physicist does. I do not particularly object to the author's choice of a name for his book; it is all right if you understand it; I am merely trying to point out that what some might expect to find under the name is conspicuous by its absence. Gibbs did not call his great work physical chemistry, and if he had, a contemporaneous reviewer might have made observations not dissimilar to mine above. And, by the way, although Lotka undoubtedly knows his Gibbs, even the "Statistical Mechanics," and often gives a type of reasoning very familiar to students of Gibbs, there happens to be no mention of that great name in the Index of Names which appears to list more than 400 persons as cited in the text. And again, by the way, if one will look at that list of names and examine the text to see how intimately ideas from very many of them are interwoven to carry forward the author's own thought, one can not but realize the long time and deep study and varied reading required to bring oneself to a position where he could contemplate writing such a book.

The simplest case is the law of population growth, dx/dt = F(X), it being assumed that the rate of that growth depends solely on the population. Here there will be equilibrium for those values of X which make F(X) = 0, i.e., the population can maintain itself at any value X, such that F(X) = 0 because then dX/dt = 0 and there is no rate of change of population. One solution is X, 0. If X is near. zero we may expand F(X) by Maclaurin's series to a single term and have dX/dt = aX, which gives the Malthusian law of growth. Evidently, too, the population may be saturated at a value X, different from zero. In the neighborhood of this value we may expand by Taylor's series to find dX/dt = a(X-X。), where for stability a is necessarily negative, and asymptotic approach to the equilibrium value from above or from below. If we consider the two roots O and X, we may write dX/dt=aX(X,-X) (X), and by neglecting (X), i.e., by assuming it does not vary appreciably between 0 and Xo, we have the Verhulst-Pearl-Reed law of population growtha law which the author shows does not hold for the growth of the rate in weight (Donaldson). By considering two variables in a similar manner one may discuss the interrelation of two populations, symbiosis, immunizing diseases, malaria-like diseases, parasitism, etc. Or by the further analysis of the growth function of a single variable one may derive certain demographic relations and conceptions which have been introduced by the author and used by him as a means of research on human populations.

From this brief discussion I intend to imply what I believe to be a characteristic of the book, namely,

Although the main underlying thought may be mathematical, there is much general philosophy of science and much general descriptive material to be found in this work, much that is as easy to read as it is interesting and instructive, not a little perhaps which is of no great importance to the work as a whole. The author knows how to write, not only in detail but in a broad way, how to lighten heavy reading with description, to intersperse chapters weighty in mathematical formulas with those entirely free of them. And what a mass and variety of material he has thus put together! It would be quite out of the question for a single reviewer either to do it justice or to point out whatever defects of judgment it may contain.

EDWIN B. WILSON

SPECIAL ARTICLES

THE ANTI-COAGULATING ACTION OF THE SECRETION OF THE BUCCAL GLANDS OF THE LAMPREYS (PETROMYZON, LAMPETRA AND ENTOSPHENUS)

THE function of the paired buccal glands in the lampreys has for a long time been a puzzle to zoolo

.......

FIG. 1. Ventral view of the head and branchial region of a Lake Lamprey to show the position of the buccal glands and the opening of their ducts. BG. The beanshaped, buccal glands at the level of the eyes (E). T. The rasping tongue. D. The duct-opening of the left buccal gland. L. The infraoral lamina. 1, 2, 3, 4, 5, 6, 7. The seven branchiopores or gill openings on the left side.

The wall of the sac-like gland is considerably folded and lined by a glandular epithelium. It is thus a combined secreting organ and a reservoir. Furthermore, for about three fourths of its circumference it has a special constricting capsule of striated muscle. In this respect it resembles the poison glands of snakes.

From the relation of the glands with the mouth, they are frequently spoken of as salivary glands, but their structure is not at all like ordinary salivary glands, and no proof has ever been given that the secretion has any digestive action.

At the only stage when these glands are present, the food of the lampreys is proteid in character, and consists almost wholly of blood from the fishes they prey upon, as one can see by examining the intestinal contents. Occasionally one may find traces of muscle or of other tissues torn (fig. 2) from its victim by the rasping tongue, but the main mass of the food as found by our many examinations has always been blood.

FIG. 2. Lake Lamprey attached to a fish. Above the pectoral and ventral fins are scars showing where other lampreys had made ragged openings with their rasping tongue.

In studying the structural arrangements of the lampreys for taking food it will be seen that the opening of the oesophagus is relatively small, and in Lampetra and Entosphenus especially, it is covered by a kind of grating. That is, the anatomical arrangement is adapted to the ingestion of liquid food. It is well known that the blood of fishes when it leaves the blood-vessels and comes in contact with the wounded tissues, clots very quickly. This is of course of great advantage to animals living in water, but it has two great disadvantages for the lampreys: It would not be so easy to swallow the clots as the liquid blood on the one hand, and on the other the clotting would tend to close the openings in the torn blood vessels and thus shut off the supply of food for the lamprey.

With this knowledge in mind, and remembering that the leech and the vampire bat have a secretion which they pour into the wounds they make in animals to prevent the blood from coagulating, it occurred to us that the lamprey's buccal-gland secretion might serve the same purpose.

Fortunately, by the aid of friends, a lake lamprey with the intestine full of blood was obtained, also some brook lampreys (Lampetra) early in the breeding season, and some of the secretion from the Pacific Coast lamprey (Entosphenus). Finally, by personal effort, many examples of the lake lamprey were caught when spawning. In all cases the secretion was obtained by aspirating it from the sac-like glands with a hypodermic syringe.

To test the hypothesis, the buccal-gland secretion of the lake lamprey was mixed with the blood of a bony fish (Amiurus), such as the lamprey often feeds upon. It entirely prevented the coagulation of the blood if in sufficient quantity. If the relative amount of blood was too great, the coagulation was delayed, but the fibrin filaments appeared in the end. In all cases the gland secretion tended to distort the red corpuscles and to haemolyze them. If the secretion was in excessive amount it extracted the haemoglobin very quickly, and in some cases seemed to destroy the corpuscles entirely, leaving only a granular mass. If the blood from the heart was put directly into the gland secretion, clotting did not occur and the corpuscles settled, leaving a straw-colored serum on top. Furthermore, when the buccal-gland secretion of a lamprey was mixed with its own blood, coagulation was prevented.

The buccal-gland secretion of all the lampreys when mixed with human blood delayed or prevented the coagulation. If a sufficient amount were used,

no fibrin ever appeared, but if a smaller relative amount were used the clotting was delayed, but the fibrin filaments finally appeared, thus resembling the action on fish blood.

For all of the experiments, the dark-field microscope was used. In this way the minutest amount of fibrin could be detected. The action was tested upon human blood from many different racial stocks -English, Norwegian, Dutch, Hebrew, etc. The action was uniform in all cases.

There was one striking difference between the action of the buccal-gland secretion of the lake lamprey (Petromyzon marinus unicolor) and that from Lampetra and Entosphenus. With the lake-lamprey secretion the human red corpuscles were prevented from forming rouleaux, but with the secretion from Lampetra and Entosphenus, the red corpuscles did form rouleaux although the fibrin formation was prevented as with the lake-lamprey secretion. In this respect, the Lampetra and Entosphenus secretion resembled the action of the sample of hirudin from the leech with which we experimented.

It is hoped that a full account of the development and structure of this interesting organ and the action of its secretion can be published with full illustrations in the near future.

SIMON H. GAGE MARY GAGE-DAY

CORNELL UNIVERSITY

EQUATION OF ELECTRONIC CONDUCTION IN UNI-POLAR NON-METALLIC FILMS THE equation for variation of current flowing through a uni-polar non-metallic film due to electronic conduction when the film is in intimate contact with a metal can be derived by the use of Poisson's potential equation, in a manner similar to the method used by Langmuir (Phys. Rev. 1913, II, p. 453; Gen. Elec. Rev. 1915, p. 330) in studying the effect of the space charge on the emission of electrons from hot filaments.

In the simple case of an infinite plane emitting surface and an infinite parallel conducting plane, we have from Poisson's equation

Considering the flow of current in the opposite direction, i.e., from film to metal with which it is in intimate relation, the emission of electrons from the film contact electrode is very feeble; first, because the two are not in intimate relation, and second, because of its reluctance to part with electrons. In this case the same form of equation as given in (6) will hold.

Insufficient data are available to verify the coefficients of equation (6). Furthermore equation (2) holds only for film thicknesses less than the mean free path of the electron so that collisions do not affect the velocity of the electron. It is therefore best to write the equation in the form

THE AMERICAN CHEMICAL SOCIETY MEETING OF THE COUNCIL

THE Council of the American Chemical Society, President George D. Rosengarten presiding, and with 120 councilors in attendance, met at Detroit on the afternoon of September 5.

The section of history of chemistry having held successfully the six meetings prescribed by the council petitioned that it be made a division of the society and this request was granted and the by-laws submitted approved. New by-laws presented by the division of chemistry of medicinal products were also approved. A proposal that a section of chemical economics should be organized was discussed and without formal vote referred to the division of industrial and engineering chemistry, under the auspices of which symposia will be held to determine interest in the subject.

A. B. Lamb, of Harvard University, was reelected editor of the Journal of the society, and associate editors Roger Adams, of the University of Illinois, and E. W. Washburn, chief chemist of the Bureau of Standards, Washington, D. C., were reelected members of his board. E. J. Crane, Ohio State University, was reelected editor of Chemical Abstracts, and H. E. Howe, of Washington, editor of Industrial and Engineering Chemistry. W. A. Noyes, of Urbana, Ill., was reelected editor of the Scientific Series of Monographs, and H. E. Howe, editor of the Technologic Series. F. A. Lidbury, of Niagara Falls, N. Y., A. D. Little, Cambridge, Mass., and C. E. K. Mees, of Rochester, N. Y., were reelected to the technologic monograph board. H. S. Taylor, of Prince

were elected as society representatives on the editorial board of the Journal of Physical Chemistry. William McPherson, of Ohio State University, was reelected a member of the society's executive committee.

The president of the society having been asked to lend his name to the national committee being organized to secure the financial participation of the United States in the erection of a Maison de la Chimie in Paris in commemoration of the centenary of the birth of Marcelin Berthelot in which memorial building is intended to house the international office of chemistry. the formation of which is to be undertaken through diplomatic channels next May, the president called upon the secretary to read the papers in the matter and to give the history of recent movements looking toward the creation in one of the capitals of Europe of international control of chemistry. Following the complete statement which included the request of the president for advice from the society's executive committee, the following was presented for the council's action:

President George D. Rosengarten, of the American Chemical Society, having asked counsel of his advisers regarding a communication from M. Maurice Leon, vicechairman of the "American Organization Committee for American Participation in a Maison de la Chimie'' requesting the use of his name as a member of the committee, the executive committee of the Society unanimously advise him to decline for the reason that his acceptance would tacitly commit the American Chemical Society to a project it can not approve.

The American Chemical Society is glad to honor the name and accomplishments of Marcelin Berthelot and in evidence thereof has appointed two of its own past presidents to represent it at the centenary celebration on October 25, 1927. An international "Maison de la Chimie" and "An International Office of Chemistry' nationally conceived with predetermined control and location in Paris is an entirely different matter to which the American Chemical Society can not give its adherence, even though it has been connected with so eminent a name as Berthelot to insure its success.

The American Chemical Society has naught but good wishes for the "Chemists' Club" of New York, the long considered "House of Chemistry" of Great Britain, the "Hofmann House" of Berlin, or for a national "Maison de la Chimie" to be located in Paris and would be glad to see any of its members, who are so inclined, contribute to their support. It can not, however, admit the propriety of any national group assuming the right to centralization of control of international chemistry within its own territory and sphere of influence, even if the major costs of construction and upkeep of such an institution were not assessed upon the rest of the world. The American Chemical Society believes that if an International Office of Chemistry, having as its object