16 
Psyche 
[February 
where the raiders entered a group of longispinosus, with part of 
the brood, had collected on the surface of the bark. They were 
huddled above the brood or moving uneasily nearby. In the 
group were several males. The importance of this observation 
cannot be minimized. It is proof positive that the actions of 
the Harpagoxenus were dulotic and not migrational. It removes 
the possibility that the nest in the log was a remnant of the mixed 
nest in process of transportation to a new site. It shows that 
the Leptothorax were aware of the presence of the raiders and, 
being unable to prevent the pillage of their nest, had resorted to 
flight to save the brood. Coupled with the actions of the raiders 
it establishes their dulosis in a manner which seems incon- 
trovertible. 
Additional evidence of a less conclusive nature was obtained 
by an examination of the raided nest. This was made on August 
9th, after a heavy thunderstorm had put an end to the raids. 
The Leptothorax colony was in no respect a remnant. No Har- 
pagoxenus were present. There were about forty longispinosus 
workers, a brood consisting largely of larvae, and a dozen virgin 
queens. The old queen I could not find. It is entirely likely 
that she had perished during the raid, but in any case the 
presence of the virgin queens is a guarantee that the colony had 
been queenless for only a short time, if at all. Alderz’s observa- 
tion that sexual forms of the slaves are sometimes present in 
mixed colonies of H. sublcevis invalidates what might be other- 
wise considered additional conclusive evidence of the individuality 
of the raided nest. However the character of the Leptothorax 
colony is at leas! not contradictory to the conclusion reached 
above. 
I shall cite one further field observation before taking up 
those made on ants in artificial nets. It may perhaps serve to 
impress the reader with the degenerate nature of the dulosis of 
Harpagoxenus. On August 5th I arrived at the mixed colony at 
2:00 P. M. The entire ledge was in the shade and no ants were 
outside the nest, although I could see the head of one in the en- 
trance. During the next three quarters of an hour a few Lep- 
tothorax left the nest and wandered about on the ledge nearby. 
During this time also the shadow had shifted, so that when at 
