36 MODES OF RESEARCH IN GENETICS 



to depreciate the value of what has been gained. 

 The studies of the last twenty years, particularly 

 in the fields of experimental embryology and cell 

 lineage, have accumulated a splendid mass of data 

 regarding the principles of somatogenesis. From 

 the standpoint of genetics, however, this material 

 is in a scattered and diffuse state. What it needs 

 is a synthetic treatment, in which all of the now 

 scattered facts of experimental embryology shall 

 be brought together and their relations to the 

 general problem of heredity clearly shown. A few 

 embryologists have, to be sure, contributed 

 notably in this direction, chiefly in this country 

 Brooks, and later Conklin, who seems to me in 

 all his work to have perceived more clearly than 

 any other recent student in this field that embry- 

 ology has a very important, if not indeed its chief 

 philosophical significance as a mode of attacking 

 the fundamental problem of heredity. In this 

 same connection the recent work of Gurwitsch 1 

 takes a high place. 



There are several reasons why the embryological 

 method has not in fact been more fruitful of 

 generalizations of value in genetics. The first, 

 and most serious, is the infrequence with which 

 the working embryologist has had any real or 

 deep appreciation of the relation of the problem 



1 Cf . for example this author's recent paper " Der Vererbungs- 

 mechanismus der Form." Arch.f. Ent. Meek., Bd. 39, pp. 516-578, 

 1914. 



