DEPARTMENT OF EXPERIMENTAL EVOLUTION.* 



C, B. Davenport, Director. 



Among the principal advances of the year have been the demon- 

 stration of the fact that the sex-behavior of pigeons can be altered 

 by injections of extracts of the germ glands; the first proof that an 

 apparently pure race may really be "heterozygous" (i. e., mixed) in 

 one sex; and clear evidence that marked aberrations may be associated 

 with a detectable chemical differentiation of the cell-sap, and that 

 development of the egg-embryo is accompanied by important demon- 

 strable changes in chemical constitution at different stages. The exact 

 method of inheritance of depressions that lead to suicide, and the sex- 

 limited nature of inheritance in certain types of nomadism and alco- 

 holism in man have been worked out, a useful hypothesis of the origin 

 of plural determiners secured, a first insight gained into the evolution 

 of the chromosomal complex (continuing work started at Columbia 

 Universitj^, under Dr. E. B. Wilson), and further experimental evidence 

 obtained of the reality of the selective nature of elimination. 



STAFF. 



The Director continued his work on heredity in poultry, sheep, goats, 

 and cats and brought the work on canaries to a close. His major work 

 has been the study of data obtained by the aid of the Eugenics Record 

 Office. From July 17 to October 20 he was absent on a journey to 

 Australasia on the invitation of the Government of New Zealand (as 

 one of an American party of about 12) and of the British Association 

 for the Advancement of Science. He gave public lectures on the work 

 of the Station and on heredity at Auckland, Wellington, and Christ- 

 church, New Zealand, and examined some of the results of the sheep- 

 breeding experiments at Canterbury, especially the so-called ''half- 

 breds" and "Corriedales." He also inspected one of the flocks of 

 Leghorn fowls that has an average yield of over 200 eggs per hen. 

 Conferences were held with sheep-breeders, biologists, and government 

 officials on matters of genetics and an effort is to be made to establish 

 a chair in genetics in the University of New Zealand. At the Sydney 

 (Australia) meeting of the British Association he read a paper on 

 "Heredity of Emotional Traits," and later he gave a public lecture at 

 the rooms of the Royal Society on "Heredity and Eugenics." He also 

 made some observations on the aboriginal Australian, both "full blood" 

 and "half caste," at Brewarrina. 



Dr. G. H. Shull has passed the entire year at Berlin in order to com- 

 plete the Burbank manuscript. He carried on experimental work at 

 the greenhouses of Prof. Dr. E. Baur of the Landwirthschaftliche 



♦Situated at Cold Spring Harbor, Long Island, Nem York. (For jjrevious reports see Year 

 Books Nos. 3-12.) 



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