32 THE GENESIS OF SPECIES. [CHAP. 



found rather to encumber than to support the theory it was 

 intended to subserve. However, the work in question 

 treats only of domestic animals, and probably the next in- 

 stalment will address itself more vigorously and directly to 

 the difficulties which seem to us yet to bar the way to a 

 complete acceptance of the doctrine. 



If the theory of Natural Selection can be shown to be 

 quite insufficient to explain any considerable number of im- 

 portant phenomena connected with the origin of species, 

 that theory, as the explanation, must be considered as pro- 

 visionally discredited. 



If other causes than Natural (including sexual) Selec- 

 tion can be proved to have acted if variation can in any 

 cases be proved to be subject to certain determinations in 

 special directions by other means than Natural Selection, 

 it then becomes probable, a priori, that it is so in others, 

 and that Natural Selection depends upon, and only supple- 

 ments, such means, which conception is opposed to the 

 pure Darwinian position. 



Now it is certain, a priori, that variation is obedient to 

 some law, and therefore that " Natural Selection " itself 

 must be capable of being subsumed into some higher law ; 

 and it is evident, I believe, a posteriori, that Natural Se- 

 lection is, at the very least, aided and supplemented by 

 some other agency. 



Admitting, then, organic and other evolution, and that 

 new forms of animals and plants (new species, genera, etc.) 



e. g., as the occasional reproduction, by individuals, of parts which they 

 have lost ; the appearance in offspring of parental, and sometimes of re- 

 mote ancestral, characters, etc. It accounts for these phenomena by 

 supposing that every creature possesses countless indefinitely-minute 

 organic atoms, termed "gemmules," which atoms are supposed to be 

 generated in every part of every organ, to be in constant circulation 

 about the body, and to have the power of reproduction. Moreover, 

 atoms from every part are supposed to be stored in the generative prod- 

 ucts. 



