298 MENTAL EVOLUTION IN ANIMALS. 



several varieties or " castes " of neuters occur in the same nest, 

 which differ widely from one another hoth in structure and 

 in instincts. The only possible way in which this difficulty 

 can be met is the way in which it has been met by Mr. Darwin, 

 viz., by supposing " that selection may be applied to the 

 family as to the individual." " Such faith may be placed in 

 the power of selection that a breed of cattle always yielding 

 oxen with extraordinarily long horns could, it is probable, be 

 formed by carefully watching which individual bulls and 

 cows, when matched, produced oxen with the longest horns ; 

 and yet no one ox would ever have propagated its kind ;" 

 and similarly, of course, with regard to the instincts of 

 neuters. Otherwise stated, we may regard the nest or hive 

 as itself an organism of which the sexual insects and the 

 several castes of neuters constitute the organs ; and we may 

 then suppose natural relation to operate upon this organism 

 as a whole, somewhat in the same way as we habitually 

 suppose it to operate upon the " social organisms " or com- 

 munities of mankind. No doubt, when carefully considered, 

 the analogy between a hive and an organism, or even between 

 a hive and a social community, is not a close analogy so far 

 as the modus operandi of natural selection is concerned ; for in 

 the one case the analogue of organs is a variety of separate 

 individuals, while in the other case there is no such great 

 contrast between different classes of a human community as 

 that which obtains among the different castes of an insect 

 community. The root of the question really consists in 

 whether or not it is possible to suppose that natural selection 

 may operate upon specific types as distinguished from indivi- 

 dual members of species. During his life-time I had the 

 advantage of discussing this question with Mr. Darwin, and 

 I ascertained from him that it had greatly occupied his 

 thoughts while writing the " Origin of Species ;" but that, 

 finding it to be a question of so much intricacy, he deemed it 

 unadvisable to enter upon its exposition. It would occupy 

 too much space were I to attempt such an exposition here, 

 and I have alluded to the subject only because I desire to 

 show that it is really this general question which is involved 

 in the case of the special difficulty with which we are now 

 concerned. On some future occasion I intend to argue this 

 general question, and then I shall hope to mitigate the force 

 of this special difficulty. I may, however, point to one fact 



