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THE AMERICAN NATURALIST [Vol. XLVII 



firm the factorial theory in the most complete and satisfactory 

 manner." In more recent papers he has given the details of 

 these extensive experiments of which only a summary is pre- 

 sented in the above paper. 



While the majority of the papers deal with plants there are 

 several upon the animal side. Of these, there may be mentioned 

 one by Walther on the coat color of horses. He considers that 

 there are two principal colors in horses' coats, viz., yellow and 

 red. These he says are allelomorphic to each other with yellow 

 dominant, These colors may be modified by supplementary mark- 

 ings such as black marks, white hairs, etc. Thus such colors as 

 brown, bay and dun would depend upon multiple factors. 



Papers by Chappellier on duck hybrids, by Noorduyn on can- 

 aries and by Houwink on fowls contain points of interest. 



Papers by Crouzon and by Drinkwater deal with phases of 

 human inheritance. 



Several papers by de Vilmorin and by Mrs. Haig-Thomas as 

 well as those by Blaringhem, von Ruemker, Collins and Kempton. 

 Johannsen, Hurst, Salaman, Swingle, and others contain many 

 interesting points which it is not possible to mention in this brief 

 account. 



The volume is well printed on good paper and the numerous 

 illustrations are well executed. A welcome feature of the volume 

 is the reproduction of photographs of the participating members 

 of the conference so far as these could be secured. 



In general the editorial work is good. However, in spite of 

 the fact that two proofs were submitted to the authors a con- 

 siderable number of typographical and grammatical errors are 

 to be found. This is particularly true in some of the English 

 summaries (cf. for example p. 130). The services of an Eng- 

 lish editor would have made these much more readable. 



The volume contains a wealth of observation which well re- 

 pay reading. It will form a welcome addition to the library of 

 students of heredity. 



Frank M. Surface 



Oroxo. Maine 



