244 BREEDING 



profitable to attempt to supply an answer until 

 information with regard to a much larger number 

 of characters of wild animals and plants than we 

 know about at present is available. But that this 

 conception does apply to a very large number of the 

 characters of domesticated races is sufficient for the 

 practical breeder. The general realisation of the 

 fact that the imit which has to be handled in experi- 

 mental breeding is not the individual animal or plant, 

 but the independently heritable unit-character, marks 

 the beginning of a new epoch in the history of the 

 practice of breeding. Once it is clearly understood 

 that dominance and recessiveness attach to char- 

 acters and not to individuals, one serious obstacle 

 to progress has been removed. And, in my opinion, 

 the most important advance which is rendered possible 

 by the removal of this obstacle will be effected by 

 a systematic inquiry into the nature and mutual 

 relationships of the characters, whether Mendelian 

 or not, which go to make up the organism. By 

 " nature " I mean whether they conform to the 

 Mendelian or to some scheme (which must then 

 become the subject of investigation) in the manner 

 of their inheritance ; and by " mutual relationships " 

 I mean whether they are transmitted independently 

 of other characters in inheritance or in association, 

 and, if so, how close the association is. This pheno- 

 menon of the association of character is a very 

 important one in practice, and may be illustrated by 

 characters of the culinary pea. The colour and 

 shape of the cotyledons are, as the reader knows. 



