270 HYBRIDISM. Chai-. VIII. 



in the sterility of a multitude of species. The evidence 

 is, also, derived from hostile witnesses, who in all other 

 cases consider fertility and sterility as safe criterions 

 of specific distinction. Gartner kept during several 

 years a dwarf kind of maize with yellow seeds, and a 

 tall variety with red seeds, growing near each other in 

 his garden ; and although these plants have separated 

 sexes, they never naturally crossed. He then fertilised 

 thirteen flowers of the one with the pollen of the other ; 

 but only a single head produced any seed, and this one 

 head produced only five grains. Manipulation in this 

 case could not have been injurious, as the plants have 

 separated sexes. No one, I believe, has suspected that 

 these varieties of maize are distinct species ; and 

 it is important to notice that the hybrid plants thus 

 raised were themselves 'perfectly fertile ; so that even 

 Gartner did not venture to consider the two varieties as 

 specifically distinct. 



G-irou de Buzareingues crossed three varieties of 

 gourd, which like the maize has separated sexes, and 

 he asserts that their mutual fertilisation is by so much 

 the less easy as their differences are greater. How far 

 these experiments may be trusted, I know not ; but the 

 forms experimentised on, are ranked by Sagaret, who 

 mainly founds his classification by the test of infertility, 

 as varieties. 



The following case is far more remarkable, and seems 

 at first quite incredible ; but it is the result of an asto- 

 nishing number of experiments made during many years 

 on nine species of Verbascum, by so good an observer 

 and so hostile a witness, as Gartner : namely, that yellow 

 and white varieties of the same species of Verbascum 

 when intercrossed produce less seed, than do either 

 coloured varieties when fertilised with pollen from their 

 own coloured flowers. Moreover, he asserts that when 



