188 A Defence of Mendel's 



appears to hold for others ; and secondly that the intensity of a 

 character in one generation of a race is no trustworthy measure 

 of its dominance in hybrids. The obvious suggestion is that the 

 behaviour of an individual when crossed depends largely upon 

 the characters of its ancestors*. When it is remembered that 

 peas are normally self-fertilised, and that more than one named 

 variety may be selected out of the seeds of a single hybrid pod, 

 it is seen to be probable that Mendel worked with a very definite 

 combination of ancestral characters, and had no proper basis for 

 generalisation about yellow and green peas of any ancestry" 

 [which he never made]. 



Let us pause a moment before proceeding to the climax. 

 Let the reader note we have been told of two groups of 

 cases in which dominance of yellow failed or was ir- 

 regular. (Why are not Gartner's and Seton's " exceptions ' : 

 referred to here ?) In one of these groups Couturier was 

 always one parent, either father or mother, and were it 

 not for Tschermak's own obvious hesitation in regard to 

 his own exceptions (see p. 148), I would gladly believe 

 that Couturier a form I do not know may be an ex- 

 ceptional variety. How Professor Weldon proposes to 

 explain its peculiarities by reference to ancestry he omits 

 to tell us. The Buchsbaum case is already disposed of, 

 for on Tschermak's showing, it is an unstable form. 



Happily, thanks to Professor Weldon, we know rather 

 more of the third case, that of Telephone, which, whether 

 as father or mother, was frequently found by Tschermak to 

 give either green, greenish, or patchwork-seeds when crossed 

 with yellow varieties. It behaves, in short, " like a green- 

 seeded pea of exceptional dominance," as we are now told. 

 For this dominant quality of Telephone's greenness we are 

 asked to account by appeal to its ancestry. May we not 



* Where was that "logician," the "consulting-partner," when 

 this piece of reasoning passed the firm ? 



