798 THE AMERICAN NATURALIST. [Vor. XXXV. 
the reproductive power in worker ants makes it possible to 
account for the conditions presented by Leptogenys and 
Tomognathus. In these genera worker forms (ergatoids) have 
usurped the functions of the winged queens, which have com- 
pletely disappeared.! 
The statements of Wasmann and other authors concern- 
ing the differences between the instincts of the queens and 
workers seem to me to require some qualification. This differ- 
ence is rather quantitative than qualitative, for the recently 
fertilized queen, even in highly specialized ants, during the 
establishment of her colony displays nearly all the worker 
instincts, even to excavating and defending the nest and caring 
for the first brood of young. In some species (Ponerinz ?) she 
may even exhibit the foraging instinct so characteristic of the 
workers, for aught we know to the contrary. It is true that 
in the more highly specialized ants like Formica, these instincts 
lapse into desuetude as soon as the workers make their appear- 
ance in the nest, but it is equally true that they may be retained 
throughout life as in the queens of the Ponerine, Leptothorax, 
and probably also many other ants. While I do not wish to 
lay unwonted stress on these fragmentary observations and 
reflections, they are, nevertheless, quite sufficient to bid us 
hesitate in the use of arguments which start from the assump- 
tion that the worker ants reproduce only under pathological 
conditions and present instincts essentially different from those 
of the queens. : 
Wasmann encounters the gravest difficulties in the genetic 
explanation of dulosis. His remarks are mainly confined to 
the two well-known cases, Formica sanguinea and Polyergus, 
the former, in the opinion of most writers, an incipiently, the 
latter a perfectly, dulotic species. He attempts to show that 
dulosis could not have arisen in sanguinea by selection, since 
flourishing or medium-sized colonies of this species could have 
derived no advantage from the possession of a small number of 
slaves, while the advantage that would accrue to a small colony 
1 Silvestri ('O1), in a paper received while these paragraphs are going through 
the press, expresses some very similar views concerning the fecundity of worker 
Termites. 
