22 
Psyche 
[February 
to the successful defeat of the defenders of the nest, there is 
ample time for altered external conditions. A heavy thunder 
shower might completely change the character of the ground 
between the two nests, efface any scent trails present, and render 
the return of the raider to its own nest extremely difficult or 
impossible. Under such circumstances there would result a 
mixed nest containing no queen but Harpagoxenus and Lepto- 
thorax workers. I found one such nest during the past summer 
and two of the nests which' Dr. Wheeler discovered near Bronx- 
ville were of this character. It seems likely that the development 
of the ergatoid females in the European sublcevis may have come 
about as a response to frequently interrupted raids. An insect 
of this type, able to participate in a raid and equally able to 
function as a queen, should a return to its own nest become im- 
possible, is at least a logical outcome of such conditions. 
An enumeration of all the mixed colonies found during the 
past summer will be given here, together with such observations 
as have not been already recorded. 
No. 1, found Aug. 4th, is the colonj^ from which the raids 
took place. Since it was never distrubed an accurate count of 
the number of ants present cannot be given. It was, however, a 
comparatively large colony and I should estimate that it con- 
tained at least a dozen Harpagoxenus workers and ten or twelve 
times that number of L. longispinosus slaves. 
No. 2, discovered on Aug. 6th, was the largest colony of any 
that were seen. It was under a stone on one of the ledges about 
thirty-five meters to the west of No. 1. Since the nest was almost 
entirely surrounded by an area of perfectly bare rock it was an 
easy matter to collect the whole colony. Stragglers that escaped 
the initial transfer were picked up with a camels-hair brush and 
placed in the artificial nest. I am certain that not more than 
half a dozen ants escaped. The colony contained a normal 
Harpagoxenus queen with vestiges of wings, 17 Harpgagoxenus 
workers, 30 L. curvispinosus workers, 206 L. longispinosus workers 
2 longispinosus males and considerable brood, most of which 
subsequently proved to be Leptothorax. The Harpagoxenus 
workers were very inactive, rousing themselves only to solicit 
