in Hybridisation 49 



THE FORMS OF THE HYBRIDS.* 



Experiments which in previous years were made with 

 ornamental plants have already afforded evidence that the 

 hybrids, as a rule, are not exactly intermediate between 

 the parental species. With some of the more striking 

 characters, those, for instance, which relate to the form 

 and size of the leaves, the pubescence of the several parts, 

 &c., the intermediate, indeed, was nearly always to be 

 seen ; in other cases, however, one of the two parental 

 characters was so preponderant that it was difficult, or 

 quite impossible, to detect the other in the hybrid. 



This is precisely the case with the Pea hybrids. In 

 the case of each of the seven crosses the hybrid-character 

 resembles t that of one of the parental forms so closely that 

 the other either escapes observation completely or cannot 

 be detected with certainty. This circumstance is of great 

 importance in the determination and classification of the 

 forms under which the offspring of the hybrids appear. 

 Henceforth in this paper those characters which are trans- 

 mitted entire, or almost unchanged in the hybridisation, 

 and therefore in themselves constitute the characters of 

 the hybrid, are termed the dominant, and those which 

 become latent in the process recessive. The expression 

 "recessive" has been chosen because the characters thereby 

 designated withdraw or entirely disappear in the hybrids, 



* [Mendel throughout speaks of his cross-bred Peas as " hybrids," 

 a term which many restrict to the offspring of two distinct species. 

 He, as he explains, held this to be only a question of degree.] 



t [Note that Mendel, with true penetration, avoids speaking of 

 the hybrid-character as " transmitted " by either parent, thus escap- 

 ing the error pervading modern views of heredity.] 



B. 4 



