1963] 
Creighton — Cryptocerus t exanus 
135 
latter assumption. The 18 queens which survived extraction were 
arranged in nine pairs and each pair was installed in a plaster observa- 
tion nest with about twenty-five workers selected at random. No 
friction developed in any of the groups thus established and it was 
found that the groups could be reshuffled at will. It was not until 
much later, when some of the groups had been isolated for months, 
that they began to act as separate entities. Even then the groups would 
combine after a brief period during which an avoidance reaction was 
displayed. Since this combination was a voluntary response on the 
part of groups which could have nested separately, it seems probable 
that the original population was a single polydomous nest. 
Through unusual good fortune one of the majors remained in the 
occluding position when the stub containing that portion of the colony 
was split open. The part of the stub which contained the nest opening 
and its adjacent nest passage was saved. The nest entrance was an 
oval with a long axis of 2.8 mm. and a short axis of 2.65 mm. With 
these proportions in mind it was easy to supply a branch containing 
a burrow whose entrance was of the proper size. After it was certain 
that this branch contained no other arboreal ants, it was placed on the 
floor of a two gallon aquarium together with one of the occupied Janet 
nests. The cover of the Janet nest was then removed and a glass top 
was sealed onto the aquarium with masking tape. The texanus workers 
at once began to explore the aquarium and soon abandoned the Janet 
nest for the burrow in the branch. With one exception the groups 
remained in the burrows. The one group which failed to do so had 
been given a branch which was rotten on the inside although it was 
sound to external appearances. When this group was given a sound 
branch they accepted it without further difficulty. 
One interesting feature of the aquarium nests was that they offered 
natural conditions for nest occlusion. It is gratifying to report that 
the phragmotic responses described in our 1954, study are essentially 
the same as those of a major which is occluding a natural burrow 
entrance. In the main this is also true of the behavior of the minor 
but one interesting difference often occurred. In our earlier studies 
the minor always entered the nest by crawling over the dorsum of the 
crouching guard (Plate 1, figs. 1-3). As the glass top of the observa- 
tion nest formed the roof of the passage, less traction was furnished 
by this glass roof than by the dorsum of the guard. But in a natural 
nest this is not true and the minors would often enter the nest by 
walking over the roof of the passage rather than over the dorsum of 
the guard. When this occurs the dorsal surface of the entering minor 
