192 THE AMERICAN NATURALIST [Vol. LIV 



that lie had grounds for questioning the universality of Men- 

 delian inheritance. But strong evidence has now heen produced 

 that blending inheritance is the regular outcome of crosses in- 

 volving multiple factorial differences. F 2 in such cases shows 

 increased variability with occasional segregation of the extreme 

 parental types, and in F 3 and F 4 such segregation becomes more 

 common. Had Whitman been able to raise F 2 and F 3 genera- 

 tions, he would undoubtedly have been convinced, contrary to 

 his expectations, as some of us have been, that blending inher- 

 itance finds adequate explanation in multiple factor Mendelian 

 inheritance. It is true that Whitman's records of hybrid birds 

 reveal sex-linked inheritance, but these records did not suffice 

 for its discovery, which fell only to those experimenters who 

 worked with the despised "domestic breeds." The most val- 

 uable part of the work recorded in this volume is probably the 

 basis which it afforded for experiments on quantitative factors 

 entering into the development and expression of sex, if not its 

 actual determination. This work is due largely to the pupil and 

 editor, Riddle, though he generously brings the name of the 

 master to the front in dealing with the subject. These results 

 have been dealt with more fully in other publications by Riddle 

 and need not here be reviewed. 



Volume 3 deals with very different subject matter from that 

 contained in Volumes 1 and 2, viz., the behavior of pigeons. 

 Here is subject matter for the trained animal psychologist and 

 Dr. Riddle felt constrained to call in a competent psychologist to 

 edit this portion of Whitman's writings. Professor H. A. Carr 

 has rendered this important service in a highly acceptable man- 

 ner. That a single biologist should be able to do distinguished 

 work in two fields so distinct as genetics and animal behavior 

 shows the breadth of Whitman's capacities and interests. The 

 reviewer is unable to deal critically with the contents of Volume 

 3, but hazards the suggestion that it contains material of very 

 great interest and of permanent value not only to the psychol- 

 ogist but also to the naturalist, the one who is interested in ani- 

 mals as animals rather than as examples and products of one 

 evolutionary process or another. 



It is much to be regretted that Professor Whitman was unable 

 himself fully to develop and round out the field of work here so 

 ably outlined and in part explored. 



W. E. Castle 



