Notes

Abstract

WE regret to notice the death of Emile Yung, professor of zoology in the University of Geneva. A typical and patriotic Swiss, Prof. Yung studied zoology under the famous Carl Vogt, and after a period of assistant-ship became his successor at Geneva some thirty years ago. For many years the treatise on “Practical Comparative Anatomy,” by Vogt and Yung, was a familiar book in zoological laboratories. It contained minute descriptions of a long series of types, and was uncommonly well done. Prof. Yung was greatly interested in the influence of environmental conditions on the organism, and made numerous experiments bearing on this problem. Thus he was one of the early investigators of the determination of sex in tadpoles, and supported the conclusion that the proportions of the sexes could be greatly altered by changing the diet. The value of this result was lessened, however, by the fact that the sex of the larvae that died in the course of the experiments was not recorded. In another investigation he showed that the growth of tadpoles was modifiable by alterations of diet; thus tadpoles fed on beef grew three times as fast as those fed on plants. The effect of diverse temperatures and illuminations was also tested; thus tadpoles reared under violet light were emphatically longer than those reared under white light, and very much longer than those reared under green light. Prof. Yung took a keen interest in the description of the fauna of Switzerland, and made many a study of the plankton of the Lake of Geneva and its seasonal variations. Many of his experimental investigations had a pleasant quality of freshness. Thus we may recall how tie took a score of marked bees from a hive near the lake, put them in a box, and liberated them in the country six kilometres away. Seventeen returned, some in an hour. Next day the seventeen were taken on a boat to a distance of three kilometres on the lake. When liberated, they flew about aimlessly, and none returned. Throughout a vigorous life Emile Yung did much for science, and his genial personality will be long remembered.