58 Riley — Presidential Address. 



advantage over another which is more elastic and variable. On 

 the contrary there are many facts which go to show that extreme 

 specialization is a disadvantage and the precursor of decrease and 

 ultimate extinction. So that natural selection, in this light, if 

 limited, as its exponents have limited it, to the production of 

 characters absolutely essential or useful to the species, must play 

 a yet more restricted part in organic variation than even I have 

 allotted to it. Social selection, as here exjwunded, implies, it is 

 true, a degree of intelligence which has unusually been denied 

 these creatures ; but the phenomena are some of them inexpli- 

 cable upon any other theory, and I have, I hope, already shown 

 how little reason we have for denying them such intelligence. 

 In a certain way the production of these specialized individuals 

 in a colony of insects may be likened to the production of 

 specialized individuals in a human community. In ne\v coun- 

 tries, like our own, the specialization has not l)ecome so marked, 

 but in the older communities of the world, the life of the indivi- 

 dual, and especially the early training and environment, produce 

 certain characteristics which permit us to stamp at once the typi- 

 cal sailor, soldier or butcher, the various artisans and the men 

 of various professions. They undergo essential modifications in 

 mind and body. Yet there is no question— or very little — of 

 selection, whether natural or artificial. The tendency to vary in 

 given directions becomes fixed through heredity, since the char- 

 acteristics of different nationalities in comparison with each other 

 cannot be so well explained upon any other view. Certain types 

 persist, and the same laws which will explain the recur- 

 rence and persistence in a promiscuous community of, say, the 

 red-headed type, whether that of atavism or any other be ad- 

 duced, will undoubtedly apply to the persistency of types 

 in the social insects. That no material or mosaic theory of 

 heredity yet propounded is satisfactory, as accounting for the 

 facts, does not affect the question, and that natural selection, 

 as expounded by Weismann and the ultra-Darwinians, fails to 

 explain the phenomena, is the very best evidence thai too much 

 is claimed for the theory. 



Invertebrate vs. Vertebrate. 



I used to be fond of speculating as to the possibilities of the 

 articulate type as exemplified in the ant, in comparison with the 



