Guides, 1,886 Handbooks, 3,087 Leaflets and 1,044 Reprints, a total of 9,022 copies. The publications of The American Museum of Natural History for the current year include the Annual Report; the Bulletin; the Anthropological Papers; Natural History, the Journal of The American Museum of Natural History; the Guide Leaflets, and the Handbooks. During 1919 Volume XLI. of the Bulletin was published, which contained three articles on mammalogy, one on ichthyology, nine on invertebrate zoology, three on vertebrate paleontology, two on herpetology, one on ornithology and one on invertebrate paleontology. Also two volumes relating to the Belgian Congo were published: Volume XXXIX., containing a monograph by Bequaert on "A Revision of the Vespide of the Belgian Congo" and a monograph by Schmidt on "Contributions to the Herpetology of the Belgian Congo "; and Volume XI., which is devoted entirely to Pilsbry's paper on "A Review of the Land Mollusks of the Belgian Congo." The collection of papers on the Belgian Congo has steadily increased; a "List of Reports on the Results of The American Museum Congo Expediton" published this year contains a short description of fifteen such papers. For the most part the members of the anthropological staff gave their time to the data obtained on former field expeditions. Problems of racial distinction and origins were developed by Assistant Curator Sullivan and Dr. Bruno Oetteking. Mr. Sullivan, with the cooperation of the department of physiology, made a series of microphotographs of racial hair cuttings for study and exhibition. His main investigation, however, concerned itself with a series of measurements upon full and mixed-blood Indians made some years ago under the direction of Professor Franz Boas. These data have been thoroughly compiled and correlated to show the results of race mixture. Among some of the significant conclusions are the constancy of degrees of correlation between bodily proportions even in mixedbloods and the apparent inheritance of specific correlations between face width and breadth of head. Dr. Oetteking completed the measurement and description of the skulls for northeastern America and eastern Siberia, for a report upon the physical anthropology of the Jesup North Pacific Expedition. Facilities for promoting research in human biology have been greatly improved during the year. A room adjoining the physiological laboratory has been equipped as an anthropometric laboratory and office for Assistant Curator Sullivan. By special arrangement the equipment of the physiological laboratory is now available for the work of this department. The Galton Society has organized a special laboratory for the study of racial characters, which, for the present, is housed in this department, the curator being the chairman of its governing committee and Assistant Curator Sullivan its director. Assistant Curator Spinden discovered a correlation between the calendars of the Aztec and Maya that promises to give an unbroken historical record for the New World from the beginning of the Christian era. Mr. Leslie Spier has completed an exhaustive study of the sun dance of the Plains Indians, revealing some interesting culture movements among these tribes. Dr. Elsie Clews Parsons has nearly completed a detailed analysis of the social organization of the Rio Grande Pueblo Indians. The Anthropological Papers deal entirely with the work of the department of anthropology. These papers are now in their twenty-ninth volume. The nine parts which appeared during 1919 include articles on various phases of the history of the Crow, Aztec, White Mountain Apache, Eskimo and Philippine tribes, and make a total of 713 pages, 125 text-figures and 3 maps. Among these articles are "Kinship in the Philippines," by A. L. Kroeber, Vol. XIX., Part III.; "Myths and Tales from the White Mountain Apache," by P. E. Goddard, Vol. XXIV., Part II.; and "The Aztec Ruin," by Earl H. Morris, Vol. XXVI., Part I. An important Guide Leaflet on "Indian Beadwork" was prepared by Dr. Wissler. The Handbook on the "Peoples of the Philippines," by A. L. Kroeber, has just appeared. It gives an interesting account of the ethnology and culture of the peoples of these islands. HENRY FAIRFIELD OSBORN NOTES ON METEOROLOGY AND THE EFFECT OF SNOW UPON THE GROWTH IT has long been believed that a snow cover is a beneficial factor in the growth of winter wheat; but some doubt has recently been cast upon this view, at least with respect to Ohio and Illinois, for which the question has been studied. Two short papers, one by Mr. Clarence J. Root1 and the other by Professor J. Warren Smith,2 have served as introductory to a longer discussion by Mr. T. A. Blair. Professor Smith draws a clear distinction between the quantity of snowfall with its subsequent effect and the effect of a snow covering, for it may well be that a very heavy snow will melt quickly and leave the ground bare for a considerable time, or that a very light snow will remain for a long time unmelted on the ground. Thus, the question of the relation of snow and winter wheat is divided into two distinct aspects. The first aspect has been discussed by Mr. Blair. His method of treating the problem is two-fold: first, by the well-known method of partial correlation, and second, by expressing the yield in linear regression equations of the form Y=a+b1x1 + b2x1⁄2 +b3x3+ . . ., in which Y is the yield; x1, X2, X3, are the various weather elements, such as mean temperature, total precipitation, sunshine, etc.; and b1, b, b, . . . are constants for a given equation depending upon the data. In expressing such relationships, the author has had to assume that there is a linear relation ... 1"The Relation of Snowfall to the Yield of Winter Wheat," Mo. Weather Rev., October, 1919, Vol. 47: 700, 4 figs. 2The Effect of Snow on Winter Wheat in Ohio," ibid., pp. 701-702, fig. 8"A Statistical Study of Weather Factors Affecting the Yield of Winter Wheat in Ohio," ibid., December, 1919, Vol. 47: 841-847, 2 figs. between the weather and yield, which, as he says, "is doubtful in cases of extreme weather conditions," and also that the most important weather influences have been included in his equations. Of the latter, perhaps the most important are temperature and precipitation, although there are many other factors which are not considered owing to lack of data, but which are more or less directly related to the weather, namely, hessian fly and other insects, severe storms, hail, and loss of crop by storm after it is cut. Taking the state of Ohio as a whole, Mr. Blair finds that there is little evidence that there are monthly values of weather elements which exert a profound influence upon the yield of wheat. After obtaining this negative result, he proceeds to treat smaller areas of the state and shorter periods than the month. First, confining his area to Fulton county, and his period to 10 days, he finds that there are certain conditions of temperature and precipitation-the former more than the latter -operative over short periods, and these are the dominant factors in determining the final yield. His conclusions, which seem to cast doubt upon the validity of the practise of the Bureau of Crop Estimates in publishing crop estimates as early as December 1, show that for the state as a whole, a warm March and June and a cool, dry May are favorable for a high yield. There are certain critical stages in the development of the plant, in which the conditions during certain 10-day periods may exert an important influence, especially in northern Ohio. It is found that the weather should be cool during the jointing stage, dry during the development of the boot, warm while the head is filling, and warm during the last ten days of stooling. As to the quantity of snowfall, it appears that a heavy fall of snow in March is detrimental. Forecasts of yield, earlier than May or June, believes Mr. Blair, can be of little value, because of the great influence of temperature during those months. The second aspect of the distinction drawn by Professor Smith, was investigated by Mr. Root in Illinois. He attempted to correlate the number of days with snow on the ground between December and March inclusive, or the number of days in March with freezing weather while the ground was bare, or even the number of days throughout the whole winter when the temperature was below 20° F. with the ground bare, with the yield of wheat in central Illinois, and in every case, he obtained a correlation coefficient so small as to cast great doubt upon the importance of the snow cover in determining the yield of wheat. More specifically, he found that there is reason to believe that wheat has a better prospect when the ground is not covered in January. The best years have been those with less than normal snowfall and with the temperature above normal for the winter. The years of poorest yield were those in which the winters had heavy snow and the temperatures were below normal. The companionship of warm winters and subnormal snowfall, and of cold winters and abovenormal snowfall, is doubtless attributable to the fact that in a warm winter much of the precipitation falls as rain and that a snow cover tends to lower surface temperatures. Studies of this type are important. It is true, however, that they are, through the complexity of weather factors and the pitfalls of the correlation coefficient, not always final in their result. Nevertheless, each serves a useful purpose in drawing the attention of agriculturists and others to the possibilities of relations or aspects of a subject which are either new or are opposed, as in this case, by a less scientific belief. C. LEROY MEISINGER SPECIAL ARTICLES TRANSFEREnce of neMATODES (MONONCHS) FROM PLACE TO PLACE FOR ECONOMIC PURPOSES SPEAKING generally, it is now beyond question that many soil-inhabiting mononchs feed more particularly on other nemas. However, they never follow these latter into plant roots, except in the case of open root cavities fairly readily accessible. They do not enter living plant tissues in pursuit of their prey. It follows that the good they do is in devouring the larvæ and young of injurious nemas at such times as the latter are accessible either in the soil or in open cavaties in the roots of plants. In transferring mononchs from place to place with a view to making use of them in combating injurious nemas, the first requisite is a supply of mononchs. Such a supply may be obtained from soils in which the mononchs are numerous, and although we have comparatively little experience to guide us, yet it is now demonstrated that supplies of mononchs existing under these conditions are available. Thus far these supplies have been discovered more or less by accident; the cases, however, are numerous enough to establish the belief that special search will lead to the discovery of a sufficient number of these original sources of mononchs to furnish an adequate supply for trial. The methods of collecting the mononchs, and transferring them, once they have been found, have been sufficiently elaborated for practical purposes, and published. In transferring the mononchs to new situations, it is of course best to pay careful attention to the relative physical and biological conditions of the two habitats-the soil from which they are transferred and that to which they are transferred. The physical and biological conditions of the two habitats should be such as to insure the persistence of the mononchs after they have been transferred from the old to the new habitat. If the climatic and soil conditions of the new habitat closely resemble those of the old habitat, there is every reason to suppose that the mononchs will survive and flourish if there is a supply of suitable food. The practical details may be illustrated by a hypothetical example. Suppose a region in Holland having a sandy soil has distributed in it as a plant pest the devastating nema, Tylenchus dipsaci, which, though more or less prevalent, is not doing very serious damage because held in check by mononchs. Suppose the existence of another region, like that in the vicinity of Bellingham, State of Washington, U. S. A., having a soil and climate similar to that of the district in Holland just mentioned, and suffering more or less severely from the ravages of Tylenchus dipsaci because this nema is not sufficiently held in check by any natural force. We may suppose that in this latter case dipsaci has been introduced at Bellingham without the enemies and parasites that hold it in check in the firstmentioned place. The mononchs found in the soil of the Holland district feeding upon Tylenchus dipsaci are collected and transported to Bellingham and introduced into the soil. There is good reason to suppose that under the new conditions, finding their food abundant, including the larvae and young of Tylenchus dipsaci, the mononchs will flourish Tylenchus dipsaci in check. If it be asked why injurious nemas are transferred from place to place without their enemies being transferred at the same time, the answer is that nemas injurious to plants are often transferred in the interior parts of plants imported in a living condition, and, as already indicated, the mononchs and other predatory nemas are less common in these situations than they are in the adjacent soil, which latter in the course of commerce often is removed from the roots and not shipped. One need only instance the case of bulbs and similar importations to see how much better chance the injurious parasitic nemas have of being imported than have those nemas which feed upon them. There is also reason to believe that sometimes the parasitic nemas infesting crops are more resistant to untoward conditions, e. g., dryness, than are the predaceous nemas. We have at the present time arrived at a stage where logically the next step is to try out the introduction of promising species of mononchs. Efforts of this kind will necessarily be somewhat expensive, probably more expensive than the corresponding early efforts to introduce beneficial insects. There can be no doubt, however, that the enormous losses due to plant-infesting nemas fully justify the expenditure of even large sums of money in an effort to apply this remedy, more particularly because the remedy, when successful, bids fair to be permanent and self-sustaining. After long-continued and intensive studies I am thoroughly convinced that many of the practises evolved in the transfer of beneficial insects can, with appropriate modification, be applied to the nemas. At the present time the greatest drawback in the case of the nemas is the small number of people who are technically competent to make the necessary biological examinations. It is in this respect principally that their introduction will differ from that of the introduction of useful insects, for the nema problem is essentially a microscopic one. Though the collection of the nemas from the soil differs entirely from the collection of beneficial insects, the methods have already been brought to such a state that there are no insuperable obstacles. The percentage of mononchs in miscellaneous collections of soil-inhabiting nemas taken from various situations is roughly indicated by the following figures based on the writer's examinations-in each case of from one thousand to several thousand specimens: 1. Miscellaneous collection from very small quantity of soil taken from the roots of 14 species of plants imported from Brazil, 6.5 per cent. mononchs. 2. Sandy soil about the roots of astilbe and peony, Holland, 11.6 per cent. mononchs. 3. Soil from cornfield in New Jersey in autumn, the prevailing genus was Mononchus. 4. Sand from Washington filter beds, 96 per cent. mononchs. N. A. COBB U. S. DEPARTMENT OF AGRICULTURE THE INTERACTION OF ETHYLENE AND SULPHURYL CHLORIDE SOME time ago, while treating suphuryl chloride (SO,Cl,) with ethylene gas (CH) at room temperature, the writer discovered a reaction quite different from any other which has come under his observation. It was noted that when a fairly strong, steady stream 1 First observed on February 28, 1918. of ethylene is passed into sulphuryl chloride at room temperature no apparent change occurs until the gas has bubbled through for quite a long while. Under certain conditions, however, the colorless liquid suddenly turns greenish-yellow, accompanied by rather a sharp rise in temperature, which during the first two or three hours of the run amounts on the average to approximately 10° C. As the temperature rises, the liquid loses its color, soon to be followed by a gradual fall in temperature, which in the course of a few minutes reaches approximately that of the room. When the gas is passed steadily through the liquid, this remarkable cycle returns again and again uniformly and continually in the same order. At the minimum temperature the liquid invariably turns greenish-yellow (about the color of chlorine), which is a sure signal that the temperature will rise. At the maximum temperature, which is usually in the neighborhood of 35° to 40°, the liquid is colorless. A complete cycle ordinarily requires from 10 to 20 minutes, depending upon conditions, and these cycles. may be observed for several hours. In the course of time, however, the cycles become longer and the differences in temperature less pronounced. This is what one would expect. A number of different runs has been made, with the same general results. The accompanying diagram shows very clearly some of the cycles observed when one of the experiments was carried out. An explanation of this interesting phenomenon has not been fully worked out, but the mechanism of the reaction is under investigation. It appears that sulphur dioxide and ethylene chloride (Dutch liquid) are among the products of the reaction. It may be that ethylene and sulphuryl chloride first unite to form an unstable compound which then dissociates into ethylene chloride and sulphur dioxide, or it may be that these products are formed by the interaction of the factors as represented by the following chemical equation: SO,C+CH,→ C2H ̧Cl, + SO2 PRINCETON UNIVERSITY WILLIAM FOSTER SATURDAY, APRIL 24 Afternoon Session 2 o'clock WILLIAM B. SCOTT, D.Sc., LL.D., president, in the chair Presentation of a portrait of the late Edward C. Pickering, LL.D., vice-president of the society, 1909-1917, by Vice-president Hale. Animal luminescence and stimulation: E. NEWTON HARVEY, Ph.D., professor of physiology, Princeton University. (Introduced by Dr. H. H. Donaldson.) The production of light by animals is due to the burning or oxidation of a substance called luciferin in the presence of an enzyme or catalyst called luciferase. It resembles the ordinary artificial methods of illumination by burning in that oxygen is as necessary for animal luminescence as it is for the light of a lamp or tallow candle. It differs in that water is absolutely essential for the light production and no carbon dioxide or heat is produced—at least no carbon dioxide or heat is produced at all comparable to that formed during the burning of such substances as tallow, either in the form of a candle or as food, to supply heat and energy for the body. Light production by animals differs also from light produced by combustion in that the oxidation product of luciferin, oxyluciferin, can be easily reduced to luciferin, which will again oxidize with light production. The reaction is reversible and appears to be of this nature-luciferin + 0 oxyluciferin + H2O. The difference between luciferin and oxy. luciferin lies probably in this, that the luciferin possesses two atoms of hydrogen which is removed to form H2O when the luciferin is oxidized. The H, must be added to reform luciferin. Whether the reaction goes in one direction or to the other depends, among other things, on the concentration of oxygen and the presence of a reducing agent. In a mixture of luciferin, luciferase, reducing agent and an abundant supply of oxygen, the reaction goes from left to right (with production of light) to an equilibrium. On removal of oxygen the reaction goes in the right to left direction with reformation of luciferin. Thus, while a firefly is flashing, oxyluciferin is produced and between the flashes oxyluciferin is reduced and is now ready to be again oxidized with light production. We may figuratively describe the firefly as a most extraordinary kind of lamp which is able to make its oil from the products of its own combustion. Not only |