190 



THE MENDEL JOURNAL 



their attention to its nature and to the goal of academic 

 destruction towards which it led by facile stages. 



Now let us examine Dr. Pearl's material with Men- 

 delian eyes. Even a cursory examination of the ninety- 

 six figures which illustrate his paper leads us to believe 

 it possible that within this so-called " homogeneous and 

 continuously variable material " there conceivably exists 

 at least four types of single comb, so far as teeth 

 characters alone are concerned. And, it is also 

 conceivable that they represent gametic types. 

 We will endeavour to enumerate and describe these 

 groups. In so doing we would desire it to be under- 

 stood that we are only indicating in a general 

 way some of the considerations a Mendeiian would 

 formulate who contemplated undertaking an investiga- 

 tion into the variation and transmission of the 



22 50 



Possible gametic types of single comb. Selected from the 9fi iigures 



illustrating Dr. Raymond Pearl's paper in " Bionietrika," Vol. VI. 



Fig. 1 to 4 indicate the types of our four hypothetical groups. 



Figs. 10, 22, 50, and 98 indicate the number of the figure in Dr. Pearl's 

 paper, from which those here figured are copied. 



[Reproduced with the kind pe'-mission of tJie, Publishers and Editors of 

 " Biometrika.") 



characters of single combs. The type comb of our 

 Group 1 is illustrated in Fig. 10 of Dr. Pearl's paper, 

 and in our Fig. 1. Around it the combs illustrated 

 in his Figs. 1, 35, 36, 42, and 44 fluctuate in one 

 direction or the other. This group is characterised 



