132 A Defence of Mendel's 



Analysis of exceptions. 



Assuming that all these "contradictory" phenomena 

 happened truly as alleged, and were not pathological or 

 due to error an explanation which seems quite inadequate 

 there are at least four possible accounts of such diverse 

 results each valid, without any appeal to ancestry. 



1. That dominance may exceptionally fail or in other 

 words be created on the side which is elsewhere recessive. 

 For this exceptional failure we have to seek exceptional 

 causes. The artificial creation of dominance (in a character 

 usually recessive) has not yet to my knowledge been demon- 

 strated experimentally, but experiments are begun by which 

 such evidence may conceivably be obtained. 



2. There may be what is known to practical students 

 of evolution as the false hybridism of Millardet, or in other 

 words, fertilisation with from unknown causes transmis- 

 sion of none or of only some of the characters of one pure 

 parent. The applicability of this hypothesis to the colours 

 and shapes of peas is perhaps remote, but we may notice that 

 it is one possible account of those rare cases where two 

 pure forms give a mixed result in the first generation, even 

 assuming the gametes of each pure parent to be truly 

 monomorphic as regards the character they bear. The 

 applicability of this suggestion can of course be tested by 

 study of the subsequent generations, self-fertilised or ferti- 

 lised by similar forms produced in the same way. In the 

 case of a genuine false-hybrid the lost characters will not 

 reappear in the posterity. 



3. The result may not be a case of transmission at all 

 as it is at present conceived, but of the creation on crossing 



