Phylogenetic tree of the various genera and families of Vespoids. (After pamphlets of his library. The Pison, under natural conditions, builds elliptical clay cells and provisions them with spiders, whereas the species of Trypoxylon nest in hollow twigs and the interstices of wall but use the same kind of prey. All these species adapted themselves to the glass tubes in the same manner. Each of them plugged the end of the tube with clay and divided the lumen into successive cells by building simple elay partitions. across it. After the cells had been provisioned, Bordage observed that the first of them were longer by half a centimeter and contained more prey than those provisioned later, and he was able to show that the larvæ in the larger, more abundantly provisioned cells produced female, the others male wasps. Similar observations have also been published by Roubaud on the Congolese Odynerus (Rhynchium) anceps, which makes clusters of straight, tubular galleries in clay walls and divides each gallery into several cells by means of clay partitions. In this case also the first cells are much longer than the later, though there is no difference in the quantity of small caterpillars allotted to the different eggs. Roubaud was able to prove experimentally that even when the amount of food is so greatly decreased that the larvæ produce adult wasps of only half the normal size, their sex is nevertheless in no wise affected. It would seem therefore that the mother wasp must discriminate between the deposition of a fertilized, femaleproducing and that of an unfertilized, male-producing egg, and regulate the size of the cell and in some instances also the amount of provisions accordingly. In the accompanying diagram (Fig. 29), taken from Ducke but somewhat modified, I have indicated the hypothetical family tree of the solitary and social Vespoids. The genera below the heavy horizontal line are solitary, and among them Eumenes and Odynerus seem to be nearest to the original ancestors, because they are very similar to the social forms in having longitudinally folded wings and in other morphological characters. It will be seen that there are six independent lines of descent to the social forms above the heavy line and that the genera plotted at different levels represent various stages of specialization as indicated by the nature of the materials and types of structure of the nests. With the doubtful exception of a few Stenogastrinæ, all the social wasps make paper nests consisting wholly or in part of one or more combs of regular hexagonal cells, in which a number of young are reared simultaneously. (To be continued) THE PROGRESS OF SCIENCE1 INTERNATIONAL COOPERATION IN INTELLECTUAL WORK STEPS have been taken toward the formation of a committee of the League of Nations on international cooperation in intellectual work. Eleven of the twelve members have been appointed and as none of them is an American, it is expected that the vacancy will be offered to an American scholar. The committee so far chosen consists of Henri Bergson, the French philosopher and author of "Creative Evolution"; Madame Curie, the Polish discoverer of radium; Albert Einstein, the German mathematician who propounded the theory of relativity; Gilbert Murray, professor of Greek at Oxford; Miss Bonnevie, professor of zoology at Christiania; D. B. Bannerjee, professor of political economy at Calcutta; A. De Castro, of the medical faculty of the University of Rio de Janeiro; J. Destree, former minister of science and art in the Belgian cabinet; G. De Reynold, professor of French literature at Berne; F. Ruffini, professor of ecclesiastical law at Turin, and L. De Torres Quevedo, director of the electro-medical laboratory of Madrid. The first meeting of this committee is set for August 1, and a prominent position on the program of work outlined is given to measures that will facilitate the interchange of scientific information and the development of higher education in the countries participating. With regard to the organization of intellectual work from an international standpoint the report adopted by the council of the League of Nations when the committee on inter 1 Edited by Watson Davis, Science Service. national cooperation in intellectual work was organized says: We are all agreed that the League of Nations has no task more urgent than that of examining these great factors of international opinion-the systems and methods of education and scientific and philosophical research. It would be unthinkable that the league should endeavor to improve the means of exchange of material products without also endeavoring to facilitate the international exchange of ideas. No association of nations can hope to exist without the spirit of reciprocal intellectual activity between its members. For example, it is clear to all how much the league would benefit by any new measures which by establishing a more definite parallelism between the diplomas of the various countries and a more frequent exchange of chairs between professors of various nationalities would lead to a more active interchange of teachers and students between nations. A still greater benefit would result from measures which permitted a rapid and more accurate communication of all work undertaken simultaneously in the field of scientific research in various parts of the world. more There is no question of detracting from the originality of national workers whose very diversity is essential for the general progress of ideas. On the contrary, the object is to enable each of these national thinkers to develop his ideas with greater force and vitality, by making it possible for him to draw more fully upon the common treasure of knowledge, methods and discoveries. As a part of the work of the League of Nations, a "Handbook of International Organizations" has recently been issued, which lists 315 societies, associations, bureaus, committees and unions, all of them international in some aspect. It is an interesting collection of religious, scientific and other sorts of organizations, the international association interested in lawn tennis being listed with the entomological, meteorological PROFESSOR SANTIAGO RAMON Y CAJAL The distinguished Spanish histologist who retires from the chair of histology and pathological anatomy at the University of Madrid on reaching his seventieth year. and other scientific societies. Such a directory is a necessary preliminary of the activities of the committee on international cooperation in intellectual work. CALENDAR REFORM REFORM of the calendar has been much discussed during the past decade or more, for the inconveniences and inconsistencies of the present calendar are obvious. The two schemes which are receiving the largest amount of attention are the international fixed calendar plan and the Swiss plan. The former, first publicly proposed by Moses B. Cotsworth of Vancouver in 1894, provides for thirteen months in the year, with twenty-eight days to the month, every date being attached to the same day of the week in every month. New Year's Day is a zero day called January 0, and is a full holiday. The extra day in leap year is a similar holiday inserted as July 0. The extra month, which, of course, does not add to the actual length of the year, is introduced between June and July, and is called "Sol." Easter is to be fixed by the Christian churches on some date between March 21 and April 26, this stabilizing an event whose drifting causes inconveniences and losses in business and social life. The Swiss plan has been advocated largely by astronomers. It also sets aside each New Year's Day and each leap-year day as independent legal holidays. The other 364 days are divided into four quarters of 91 days each, each quarter containing one month of 31 days and two months of 30 days, thus keeping twelve months as at present. The international fixed calendar plan recently received the unanimous approval of a convention held in Washington by those interested in calendar reform. The American section of the International Astronomical Union, after considering both the Swiss plan advocated by its committee on calendar reform and the fixed calendar plan, recently refused to take action on the matter. The question of calendar reform was taken up at a meeting of the International Association of Academies held in St. Petersburg in 1913, and a committee was appointed on that occasion "to study questions relative to the unification and simplification of the calendars and the fixing of the date of Easter.'' This committee would have made a report in 1916, but for the war. Another discussion of this subject took place at the International Geographical Congress held in Rome in 1913. In June of the same year the World Congress on International Associations, which met at Brussels, passed a resolution urging the governments of the world to adopt a universal calendar. Three of the International Congresses of Chambers of Commerce have given expression to the same desire. Finally, just before the outbreak of the world war, the International Congress on the Reform of the Calendar held its sessions at Liège, and not only agreed to urge the adoption of a universal and improved calendar but also made plans for a formal conference, which was to have been convoked in Switzerland at the invitation of the Swiss government. but was never held. In the future there may come a conference of nations that will adopt a new and more logical calendar as easily as standard time was established by an international conference at Washington about forty years ago. INVISIBLE SUN-SPOTS DR. GEORGE ELLERY HALE, director of the Mount Wilson Observatory, has announced the discovery of invisible sun-spots. In 1908 Dr. Hale found that a sun-spot is a great whirling storm, similar to a terrestrial tornado, but on a gigantic scale, often vastly larger than the earth. The ex |