GENETIC STUDIES OF SEVERAL GEOGRAPHIC 

 RACES OF CALIFORNIA DEER-MICE 1 



DR. FRANCIS B. SUMNER 

 Scripps Institute, La Jolla, Cal. 



Some of those present may recall a resolution which 

 was adopted at a meeting of the Biological Society of the 

 Pacific, held in Berkeley, in April, 1913, endorsing a 

 project for the study of certain problems, related both to 

 genetics and to geographical distribution. During the 

 same year, the Scripps Institution for Biological Re- 

 search found it possible to undertake the execution of this 

 project, and the author of the present paper was chosen 

 to carry it out. It is my object to-day to offer a pre- 

 liminary report upon the results of these studies. 



To those who have been so fortunate as to work in 

 fields which yield quicker returns than does that of ex- 

 perimental breeding, it may seem that something more 

 than a "preliminary report" might reasonably be ex- 

 pected after the lapse of a year and a half. If any justi- 

 fication is needed for such seeming slothfulness, I need 

 only remark that my studies have already necessitated 

 the trapping of about 600 living mice, of my chosen 

 species, in four widely distant parts of the state, together 

 with the rearing of several hundred others which were 

 born in captivity; and that I have made measurements 

 of some 500 of these animals, including skeletal measure- 

 ments of over 400. Care of this rather large family of 

 pets, statistical treatment of the measurements, continu- 

 ous meteorological observations at several points, and the 

 preparation of a certain number of skins and color photo- 

 graphs, are also to be included in the technique of this 



i Bead before a joint meeting of the American Association for the Ad- 

 vancement of Science (Section F), the American Society of Naturalists, 

 the American Society of Zoologists, the American Genetic Association, and 

 the Eugenic Research Association, at Stanford University, August 4, 1915. 

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