20 
Psyche 
[February 
during the absence of the Harpagoxenus from the cavity a cur- 
vispinosus entered and secured a part of the brood, and once the 
raider returned in time to drive away two others who were about 
to enter. During the foregoing period most of the Leptothorax 
had collected in two groups on the floor of the nest, the larger of 
which contained the queen and the majority of the brood carried 
out of the cavity. The Harpagoxenus now began to pass close to 
the curvispinosus. At 4:19 it approached the smaller group and 
attacking the workers, drove them away from the brood. This 
it examined with great care, touching the larvae and pupae with 
its antennae. Two curvispinosus workers which attacked it 
in a half-hearted manner were quickly driven away. To my sur- 
prise it left the brood unmolested and turned to the larger group 
of Leptothorax which was now in great confusion. Some of them 
the Harpagoxenus drove away, attacking so vigorously two 
workers burdened with pupae, that the pupae were abandoned 
and their bearers put to flight. It then attacked a curvispinosus 
callow and soon afterwards bit off the antennae of a worker. At 
4:28 it returned to the cavity having taken no further notice of 
the brood. At this point the observations were interrupted for 
an hour and a half. When I returned the Harpagoxenus had left 
the cavity and had been seized by three curvispinosus workers. 
All of its former spirit and activity was gone, nor did it ever again 
manifest these characteristics. It lay supine and unresisting on 
the floor of the nest, its antagonists attached to its legs with 
locked mandibles. This was the condition at 10:00 P. M. How- 
ever by next day it had freed itself and, to judge from the dim- 
inished brood of the Leptothorax, had carried a number of larvae 
and pupae into the cavity. At 11:17 A. M. it emerged, secured 
a pupa and returned with it to the cavity. The disorganization 
of the Leptothorax was complete. Twenty dead or dying workers 
were scattered about the nest. The queen lay on one side ap- 
parently dead. The remaining workers moved aimlessly about, 
a few carrying pupae or larvae. They no longer resisted or ran 
from the Harpagoxenus but stood perfectly quiet when it ap- 
sroached, and even allowed it to touch them with its antennae, 
by the following day the Harpagoxenus had obtained practically 
all of the curvvspinosus brood. Only five larvae and pupae remain- 
