796 THE AMERICAN NATURALIST. [VoL. XXXV. 
ant of sporadic occurrence? As well might we expect the 
human dermis and its appendages to present hereditary modi- 
fications in adaptation to occasional parasites like Pediculus 
capitis. The advantages that would result from the develop- 
ment of a courageous disposition and specially protective forms 
of nest architecture in F. fusca and pallide-fulva are more 
than outweighed by those derived from their unusual powers 
of reproduction. These species run to offspring, not to valor. 
That the survival and even the predominance of species does 
not necessarily depend on the development of moral and 
psychic endowment is demonstrated on a grand scale in the 
vegetable kingdom. 
This defense of McCook's argument is, ipsc only a 
small portion of Wasmann's criticism of the position held by 
Darwin, Forel, and Lubbock in regard to the phylogeny of the 
mixed colonies ('91, pp. 214-254). Wasmann sees in these same 
facts irrefutable arguments against the theory of indeterminate 
variation and natural selection, and arguments equally strong 
in favor of tracing the modicum of physical and psychical 
development which is acceptable to him to *'innere gesetz- 
mássig wirkende Entwicklungsursachen." In my opinion, 
he has succeeded — if indeed he has really succeeded — 
only in showing that the genetic method has been somewhat 
awkwardly applied to the cases of compound and mixed nests. 
On the whole, I believe that he has neither invalidated the 
principle of natural selection, nor made it perfectly clear that 
we must forthwith deliver ourselves up to anything so impal- 
pable as “innere gesetzmüssig wirkende Entwicklungsursa- 
chen." In support of these statements the following remarks 
on some of Wasmann's arguments are offered. 
Wasmann seems to regard it as an established fact that 
worker ants do not reproduce, or do so only under unusual or 
even pathological conditions. He is also inclined to emphasize 
the differences between the instincts of the queens and those of 
the workers. Hence the workers are debarred from transmit- 
ting their peculiar characters, either congenital or acquired, 
and the instinct modifications, so characteristic of different 
species of ants, must be explained as arising from determinate, 
