242 ILLEGITIMATE OFFSPBING OF Chap. V. 



afterwards legitimately with pollen from a short-styled 

 dark-red polyanthus which is a variety of P. veris ; 

 and the result was that every one of the thirty seed- 

 lings thus raised bore flowers more or less red, show- 

 ing plainly how prepotent the legitimate pollen from 

 a short-styled plant was over the illegitimate pollen 

 from a long-styled plant. 



In all the several foregoing points the parallelism is 

 wonderfully close between the effects of illegitimate 

 and hybrid fertilisation. It is hardly an exaggeration 

 to assert that seedlings from an illegitimately fer- 

 tilised heterostyled plant are hybrids formed within 

 the limits of one and the same species. This conclu- 

 sion is important, for we thus learn that the difficulty 

 in sexually uniting two organic forms and the sterility 

 of their offspring, afford no sure criterion of so-called 

 specific distinctness. If any one were to cross two 

 varieties of the same form of Lythrum or Primula for 

 the sake of ascertaining whether they were specifically 

 distinct, and he found that they could be united only 

 with some difficulty, that their offspring were extremely 

 sterile, and that the parents and their offspring re- 

 sembled in a whole series of relations crossed species 

 and their hybrid offspring, he might maintain that his 

 varieties had been proved to be good and true species ; 

 but he would be completely deceived. In the second 

 place, as the forms of the same trimorphic or dimorphic 

 heterostyled species are obviously identical in general 

 structure, with the exception of the reproductive 

 organs, and as they are identical in general constitu- 

 tion (for they live under precisely the same condi- 

 tions), the sterility of their illegitimate unions and 

 that of their illegitimate offspring, must depend ex- 

 clusively on the nature of the sexual elements and 

 on their incompatibility for uniting in a particular 



