•1-2 rilE GENESIS OF SPECIES. [Chap. 



difficulties exactly Avliere tliey were. It is a question, also, 

 whether tlie hypothesis of " Pangenesis " ^ may not he 

 found rather to encumber than to support the theory it is 

 intended to subserve. However, the work in question 

 treats only of domestic animals, and probably the next 

 instalment will address itself more vigorously and di- 

 rectly to the difficulties which seem to us yet to bar the 

 way to a complete acceptance of the doctrine.- 



If tlie theory of Xatnral Selection can be shown to be 

 (juite insufficient to explain any considerable numl)er of 

 important phenomena connected with the origin of species, 

 that theory, as the explanation, must be considered as 

 so far discredited. 



If other causes than Natural (including sexual) Selection 

 can be proved to have acted — if variation can in any cases 

 be proved to be subject to certain determinations in special 

 directions bv different means than Natural Selection, it tlien 

 becomes antecedently probable that it is so in other cases, 

 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 ^yr'wri, that variation is obedient to 

 some law, and therefore that " Natural Selection " itself 



* *' Panf^cncsis" is the name of tlie iifw tlieory ]>ropo.seJ hy Mr. 

 Darunn, in onler to account for various obscure physiolo^xioal focts, .sucli, 

 «.gr., as the occasional reproiluction, l>y individuals, of parts which they 

 have lost ; the ap]»earance in otfsjtrinj^ <>f parental, and sometimes of remote 

 ancestral, chara<'ters, &c. It accounts for these jihenomcna liy .snpjinsing 

 that every creature ])ossesses countless indefinitcly-minute organic atoms, 

 termed *' gemmule.s,'' which atoms are suj)j)osed to he generated in every 

 part of erery organ, to l)e in constant circulation about the )x)dy, and to 

 iiave the power of repn)duction. Moreover, atoms from every part are 

 suppnseil to be stored in the generative products. 



- Tiiese anticipations of the Author have not been fully realized in 

 Mr. Darwin's most recent work, "The Descent of Man." 



