32 NATIONAL TRENDS IN BIOLOGY 



is that they are unable to formulate a question so as to 

 get an intelligent answer, and much of the objection and 

 faultfinding regarding Mendelism is probably due to this 

 same fact. 



Any new idea thrown into the biological arena would 

 not only cause great numbers of men to follow experimen- 

 tally the lead thus given, but the lesser leaders would be 

 inclined to break into new paths, also, though usually into 

 closely related fields. So we find papers on genetics and 

 heredity with emphasis on variation appearing one after 

 another, and almost simultaneously, others on behavior 

 and physiology. This work on physiology concerned itself 

 primarily with the reactions of mature organs, and did 

 excellent work for "medicine." But not long afterward 

 others drove the problem further back, and the question 

 of how the organism arose in the first place, was given a 

 niche in the gallery of experimentation. However, this be- 

 ginning of embryology was largely descriptive, accounts 

 being written merely of what was seen. From this descrip- 

 tive work, in turn, real experimental embryology was 

 born. Now, men such as William Roux and Hans Driesch, 

 began destroying or removing parts of the early embryo 

 to ascertain what would happen. 



Roux's single pioneer experiment of note consisted in 

 killing one of the first two cells of the dividing egg of a 

 frog. The remaining half produced only a half embryo. 

 Driesch, on the other hand, found that with one-half egg 



