794 THE AMERICAN NATURALIST. (Vor. XXXV. 
has been specialized. In other words, if Lucidus has become 
specialized as a warrior, dropping an original disposition and 
ability to labor, her slave has not become specialized as a 
worker, nor dropped her combative faculty, but seems to be 
possessed in all respects of the riormal habits and nature of 
ants of her species. At least I could trace in her no effects 
of slavery, other than the strange association with and care of 
her abductor. One, therefore, who accepts Dr. Darwin's sug- 
gestion, must allow that natural selection has wrought toward 
specialization in one section of the colony, but has been sus- 
pended in its operations upon the other section. It is doubt- 
ful if the anomalous conditions thus raised by Dr. Darwin's 
explanation be not more difficult to explain than the original 
conditions to which the hypothesis was applied." 
Assuredly, if all the arguments against natural selection were 
as easily refuted as the one here produced by McCook, Dar- 
win's followers would have occasion for great rejoicing. The 
refutation is equally easy whether we consider the colonies of 
the auxiliary species with which Polyergus wars, or only the 
larvae and pupz which it abducts from these colonies and rears 
as its slaves. So far as the latter are concerned, McCook has 
completely overlooked the very obvious fact that Polyergus 
rears only the workers of the auxiliary species, and these have 
never been known to reproduce in the mixed nests. But even 
if we suppose, for reasons to be given below, that these workers 
may often reproduce normally, the difficulty is not removed, 
since they would not .only have to be able to transmit charac- 
ters acquired in their imaginal stage, — and the possibility of this 
has by no means been demonstrated, — but they would have to 
transmit these characters to male or female offspring if there 
was to be any permanent modification of the species. Now 
this is impossible, because Polyergus will not permit the winged 
sexes of the auxiliary species to reach maturity. Hence the 
detached auxiliaries cannot impart any modifications to the 
species to which they belong, no: matter what peculiarities 
they may take on in the Polyergus nests. 
Though the fallacy in McCook's argument is very obvious, 
Wasmann still contends that it involves “ einen vorzüglichen 
