THE SELF-FERTILIZATION OF PLANTS. 359 



characters of their species, need never cross, if their 

 type is never modified. With them, a cross must needs 

 entail evil upon them, instead of good. For, the only 

 variety with which they could possibly cross, must 

 necessarily be one, distinguished from them, by nega- 

 tive features, which ever work evil. 



But, when individuals are deficient in some of the 

 characters of their species, it is necessary, in order for 

 good to accrue to their offspring, — in order for the 

 physiological evil, attendant upon their structural de- 

 fects, to abate, — that they regain the characters they 

 lack. It is a law of nature, that all the characters, of a 

 species, should be developed, in every individual of 

 such species. The good accruing from a cross, is not 

 due to crossing, per se, but to that accession, of extra 

 characters, which a cross generally involves. The 

 good flows, from the repair, made to the lost integrity, 

 by the addition, in the offspring, to the one set of char- 

 acters of one variety, of another set of characters of 

 another variety. Darwin would be correct, were he to 

 say, that an advantage frequently results from the act 

 of crossing two varieties ; for, each generally possesses 

 characters which the other lacks. But, when indi- 

 viduals have the complement of characters, necessary 

 to fertility, they may long continue their breeding 

 without crossing. 



The instances, which Darwin cites, of the enclosed 

 flowers, which are incapable of crossing, alone being 

 fertile; and, the instances of other plants of the same 

 species, which are sterile, are fully explicable, upon 

 the theory, that the reason why the enclosed flowers 



