134 
Psyche 
[September 
boring beetle larvae. The burrows most often selected are those of 
anobiids, bostrychids and some of the smaller buprestids. Under 
normal conditions each burrow consists of a long, slender, unbranched 
tube which opens to the outside at one end and terminates in a blind 
pocket at the other. The portion of the burrow just behind the opening 
curves inward but the rest of it roughly parallels the long axis of the 
branch. A branch whose diameter is 4 cm. or more may be traversed 
by several closely adjacent but completely separate burrows. This 
arrangement permits a number of beetle larvae to occupy the same 
branch without interference. By the time that the adult beetle emerges 
the branch is dead and the burrow is partially filled with detritus, 
which is mainly composed of small bits of cellulose that have passed 
through the gut of the beetle larva. The consistency of this material is 
similar to that of fine, tightly compacted saw-dust. This detritus must 
be removed before the ants can occupy the burrow, but its removal is 
not difficult and the process has little in common with the driving of 
a passage through sound wood. When the detritus has been removed 
what is left is a prefabricated burrow whose walls consist of hard, 
sound wood and whose entrance is of a size that can be occluded by 
the major. The branches in which texanus nests are largely or entirely 
devoid of bark. Branches which do not lose their bark are usually 
softened by dry rot. Such rotten branches often contain burrows but 
the ants seldom occupy them. 
The behavior just discussed produces the problem of polydomy in 
texanus. A branch which has been extensively tunneled may contain 
several groups of texanus workers each living in a separate burrow. 
If it can be shown that only one of these groups contains a queen the 
probability is that the several burrows contain parts of a single, polydo- 
mous colony. But when each group contains one or more queens it is 
impossible to state whether one is dealing with several separate colonies 
or a single polydomous colony. The matter becomes even more com- 
plicated when several adjacent branches house groups of texanus 
workers. This was true of the population on which this study was 
based. The ants occupied burrows in the stubs of six dead branches, 
all attached to a single living branch of a live-oak (Quercus virginiana 
Nee). The total population of the six stubs consisted of approximately 
275 individuals of which 23 were queens. Since the number of queens 
in each stub varied from two to five, it was impossible to say whether 
the six groups were separate colonies or parts of a single polydomous 
colony. As it was advantageous to have a number of equivalent groups 
for the work that was contemplated, it was decided to proceed on the 
