2 
Psyche 
[March - June 
The next factual data on militicida came to light a year or two 
later when W. M, Mann excavated nests near Benson in August 
and found both majors and minors living in them. These majors 
corresponded to the remains that Wheeler had taken earlier. With 
both major and minor castes available, Wheeler was in the position 
to describe militicida as a new species, which he did in 1915 (1). 
If Wheeler had been content to let the matter rest with the de- 
scription of these two castes his action could have been defended not 
only as sound but also as conservative, for he had waited until the 
majors and minors had been certainly associated before presenting 
his description of them. But Wheeler was not content to limit his 
efforts to the description of militicida. He proceeded to develop a 
striking hypothesis as to its habits. This was so plausibly presented 
that one is apt to forget that this highly ingenious account is pri- 
marily compounded of supposition. Because Wheeler had found no 
majors in the Benson and Hereford colonies, he assumed that none 
were present. Because he had found the remains of majors on the 
chaff piles of these colonies, Wheeler assumed that all the majors in 
the colonies had been slaughtered by the minors. Having made these 
two assumptions Wheeler was forced to make others to support them, 
for this astonishing behavior on the part of the minor clearly demanded 
explanation. This Wheeler supplied as follows: 
“It appears, therefore, that all the individuals of this caste (the 
majors) are regularly killed off by the workers on the approach of 
winter, probably after they have broken open all the hard seeds col- 
lected by the workers. Such a slaughter of the members of a large 
caste during the season when their activities are no longer required, 
when they would simply be a burden on the colony by consuming 
stored food and when fresh food cannot be collected, must have great 
advantages. Although I have never noticed this behavior in any 
other species of Pheidole , I believe that a study of the harvesting spe- 
cies with very large-headed soldiers in the deserts of the southwest 
may bring other similar cases to light.” 
It is obvious that the most direct way to test Wheeler’s theory 
would be to examine the nests of militicida during the winter months. 
If such examinations were properly carried out it would be possible 
to state with certainty whether or not majors are present in the nests 
at that time. But subsequent observations on militicida have all 
been made during the summer. The writers observed this ant at 
Safford, Arizona, in July 1950. In August, 1952 A. C. Cole studied 
colonies at Bayard and Deming, New Mexico, and in August 1956 
