12 MODES OF RESEARCH IN GENETICS 



regression coefficients to the values given by 

 Galton, which were admittedly determined from 

 meager material. 



Looking critically at the biometric method of 

 studying heredity and the results which it has 

 achieved, there are two points which seem partic- 

 ularly to require discussion. First, it appears 

 clear that this method attacks the problem at 

 what might be called its lowest level. In other 

 words, the biometric method deals only with the 

 element of the problem which was designated as 

 A in our preceding analysis (cf. p. 3). As it has 

 been developed in the hands of its chief devotees 

 the biometric method of attack fails entirely to 

 recognize any real or essential significance to the 

 elements B, C, and D of our analysis ; that is to 

 gametogenesis, somatogenesis, or the specificity 

 of the germinal substance. Herein lies, in the 

 opinion of biologists generally, I think, the chief 

 weakness of the results. These results constitute 

 essentially no more than a rather precise de- 

 scription of the most superficial external features 

 of the phenomena of heredity. Except only in 

 the simplest of events (and then not directly) 

 a description, however minute, of those events 

 cannot give the slightest real evidence as to their 

 cause. A scientific visitor from another planet 

 might describe minutely the curious polymor- 

 phism to be observed amongst human beings in 

 respect of the amount and distribution of the 



