COMBS OF FOWLS 187 



which have been selected by the fanciers ? If it is this 

 latter alternative, then we imagine that the selection of 

 plumage, of size, of habit, of form, and other characters, 

 has played an equally important part, probably a more 

 important one, than that of the selection of comb charac- 

 ters. And, if this is so, the Biometricians are not justified 

 in believing that the single combs of this race — and it is 

 with this character that they are alone dealing — is any- 

 thing else than markedly heterogeneous. Even though 

 a special selection of comb characters on the basis of old 

 conceptions* and by old methods had been made, there 

 would, even then, have been no reason to regard the 

 material as homogeneous. But even this has not been 

 done ; for Dr. Pearl himseK informs us on page 428 : 

 " The drawings and figures here presented show that in 

 the absence of special selection1[ in regard to comb size, 

 the character. shows a range of variation all the way from 

 the condition shown in large combed types in Leg- 

 horns to the very smallest of single combs." It is clear 

 then, on the admission of Dr. Pearl himself, there has 

 been no special selection exercised in regard to one of 

 the characters of the comb, namely, size, the variation of 

 which he set himself the problem to measure and describe. 

 How, in the face of this admission, his material can be 

 described as "so homogeneous that it would be difificult 

 to find any material more so," appears to us to be an 

 aberration of enthusiasm not perhaps difficult to com- 

 prehend. We are therefore compelled to dismiss as 

 untenable the claim that this biometrically chosen mate- 

 rial is homogeneous in any but the fanciers' sense of 

 the term. 



Let us pass to a further consideration of the problem. 

 We will take one only of the many characters exhibited 

 by the single comb, namely, its size. Now what is size ? A 



* The old conceptions alluded to here are those which flow from the 

 belief that the visible body characters are a true and trustworthy criterion 

 of gametic constitution. We now know that in the majority of cases this 

 is not so. The old methods alluded to are those which are based on this 

 old belief, and which consist in selecting individuals because of their external 

 or visible body characters. The Mendehan or newer biological method is 

 to select them because of their gametic constitution, which is judged of 

 by their genetic behaviour, manifested in the course of experiment, 



■[■ The italics are ours. 



