1 98 A Defence of Menders 



similar " ; when he speaks of Mendel having obtained his 

 results with "a few pairs of plants of known ancestry*," he 

 means "a few pairs of known plants" and no more ; when 

 he writes that "the law of segregation, like the law of 

 dominance appears to hold only for races of particular 

 ancestry!," the statement loses nothing if we write simply 

 " for particular races." We all know the Mendelian, best 

 of all that particular races and particular individuals 

 may, even though indistinguishable by any other test, 

 exhibit peculiarities in heredity. 



But though on analysis those introductions of the word 

 "ancestry" are found to add nothing, yet we can feel that 

 as used by Professor Weldon they are intended to mean a 

 great deal. Though the appeal may be confessedly to 

 ignorance, the suggestion is implied that if we did know 

 the pedigrees of these various forms we should then have 

 some real light on their present structure or their present 

 behaviour in breeding. Unfortunately there is not the 

 smallest ground for even this hope. 



As Professor Weldon himself tells us:}:, conclusions from 

 pedigree must be based on the conditions of the several 

 ancestors ; and even more categorically (p. 244), " The 

 degree to which a parental character affects offspring depends 

 not only upon its development in the individual parent, but 

 on its degree of development in the ancestors of that parent." 

 [My italics.] Having rehearsed this profession of an older 

 faith Professor Weldon proceeds to stultify it in his very 

 next paragraph. For there he once again reminds us that 

 Telephone, the mongrel pea of recent origin, which does not 

 breed true to seed characters, has yet manifested the peculiar 

 power of stamping the recessive characters on its cross-bred 



* See above, p. 187. t See above, p. 184. 



| See above, p. 186. 



