180 Psyche [December 
by the large size and dark color of the ants and their wings, the 
stillness and purity of the air and the unobstructed view over the 
level desert. Unfortunately our haste to reach Phoenix before 
night and the prospect of a very muddy road ahead, made it 1m- 
possible to stop and observe the conclusion of the flight and the 
subsequent behavior of the versicolor queens. On previous visits 
to Arizona I had found the species in the neighborhood of Benson, 
Tucson and Yucca. The past summer I took it also near Oracle 
in the Santa Catalina Mountains, near Casa Grande and a few 
miles from Texas Pass on the western slopes of the Dragoon 
Mountains. In all these localities the colonies are sporadic and 
by no means abundant so that it is difficult to account for the vast 
number of males and females engaged in the flight described 
above, unless we assume that they represented the entire annual 
sexual output of a large number of colonies distributed over a 
very extensive territory. 
THE PLEOMETROSIS OF MYRMECOCYSTUS. 
By Wivu1am Morton WHEELER. 
It has long been known that the colonies of some species of ants 
never possess more than a single fertile queen, whereas in other 
species several such queens are normally present. Wasmann has 
recently named the former condition “haplometrosis,”’ the latter 
““pleometrosis.”"! Among North American ants the species of 
Camponotus, Polyergus, Pogonomyrmex, Aphenogaster and Lasius 
are normally haplometrotic, whereas the species of Formica, 
Tapinoma, Crematogaster, Pheidole, Monomorium and Myrmica are 
pleometrotic. This condition undoubtedly arises in most colonies 
secondarily from a primitive haplometrosis through the deilation 
and adoption of one or more daughter queens. Large colonies of 
Formica obscuriventris, e. g., often contain a number of daughter 
queens in various stages of deiilation. The number of queens thus 
accumulated in some colonies is considerable. J have counted 
more than thirty in a single medium-sized colony of the typical 
F. fusca, and a single mound of F. easectoides may contain nearly 
1These terms are equivalent to ‘‘monogyny”’ and ‘‘polygyny’’ employed by students of the 
social wasps, though somewhat more expressive as they call attention to the maternal or nurs- 
ing activities. 
