402 THE SELF-FERTILIZATION OF PLANTS. 



close-interbreeding, has ever been (in his " Origin of 

 Species," and in his "Animals and Plants under Domes- 

 tication") the lessened fertility, or the sterility, of the 

 individuals so impregnated. And, the test is also that, 

 required by the theory of reversion. Such theory, of 

 Reversion, maintains, that, where there is little, or no 

 modification, there are no, or very little evil effects 

 occasioned by the process, in question. If, then, there 

 is, in some of the Orchids, the modification which en- 

 tails the mechanical incapacity for self-fertilization ; 

 and, if there is an absence, of such modification, in 

 others of the Orchids, the test of fertility — which is 

 the test with either theory — should, upon Darwin's 

 theory, show that the modified plants (which are ever 

 crossed) are superior, in fertility, to the plants capable of 

 self-fertilization ; whereas, upon the theory of reversion, 

 or proportionate development, it should show, that it 

 is the less modified plants (which, in this case, are the 

 self-fertilized ones) which are more fertile than the ones 

 which are crossed, and which have parts which are 

 structurally and functionally rudimentary. 



Darwin, as above remarked, has, in his works to 

 which this "Fertilization of Orchids" is merely sup- 

 plementary, clearly defined what he means, by the evil 

 effects of the process of close-breeding. He there ever 

 states, and states explicitly, that those effects are, prin- 

 cipally, lessened fertility, and sterility. In all of the 

 phenomena, adduced in his former works, his test has 

 not, to his mind, conclusively failed him. With the 

 light, derived from the theory of reversion, the phe- 

 nomena mentioned may be proved (as already shown), 



