STERILITY OF HYBRIDS. 411 



other in external appearance, cross with perfect facil- 

 ity, and yield perfectly fertile offspring." 



On page 200, Origin of Species, he says : 



" How can we account for species, when crossed, 

 being sterile, and producing sterile offspring, whereas, 

 when varieties are crossed, their fertility is unim- 

 paired !" 



Again he says, page 236, Vol. i, Animals and 

 Plants, &c: 



"* * The more distinct the breeds, the more 

 productive are their mongrel offspring." ! 



In divers other portions of his works, he has, as 

 has already been shown, also declared, that the more 

 divergent the breeds, the less fertile are the individuals 

 of each variety, when bred inter se. He says, that in- 

 dividuals of divergent varieties are extremely liable to 

 sterility, degeneration, and death, when bred inter se ; 

 and that crossing needs must be resorted to, all the 

 time, with such individuals, in order to remedy such 

 sterility, and prevent their extinction. 



So, it is manifest, that the " modifications which are 

 slowly impressed on the reproductive systems," tell a 

 tale, not only in refutation of his " view," but also in- 

 finitely more significant of the falseness of his theory, 

 than is even the sterility of hybrids. The facts prove, 

 that the sterility of hybrids has not been acquired, as the 

 varieties diverged. The facts, on the contrary, prove, 

 that varieties grow more and more unlike distinct spe- 

 cies, the further they diverge. The facts show, that 

 the varieties not only do not acquire sterility, in their 

 crosses, as they diverge in character; but that, as they 

 36 



