878 THE AMERICAN NATURALIST. [Vor. XXXV. 
Until very recently the genus has been characterized as 
presenting no forms intermediate between the workers and 
soldiers, in contradistinction to the Old World genus Pheido- 
logeton, the species of which exhibit even in the same col- 
ony numerous intermediates between the gigantic, big-headed 
soldiers and the minute workers. During the past year I 
found that two of our Texan and Mexican species of Pheidole 
(Ph. kingii André, ver. instabilis Emery, and PA. vaslitit Per- 
gande) resemble Pheidologeton in presenting, in the very same 
nest, complete series of intermediates.! My attention was 
directed to this singular condition by Professor Emery, who 
has described the Texan ZZ. instabilis from specimens col- 
lected at Austin. He has also rectified the synonomy of the 
Mexican Ph. tepicana Pergande, which presents a like poly- 
morphism and has therefore led to the description of several 
species from soldiers of different dimensions? Recently Pro- 
fessor Forel, utilizing some observations which I made at 
Queretaro, Mexico, has been able to rectify a similar error 
in the synonymy of PA. vaslitit Pergande.? 
In the present paper I desire to call attention to another 
peculiar modification of the workers of Pheidole, traceable to 
a perfectly definite, though obviously very different cause from 
that which must bring about the above-mentioned di- and poly- 
morphism. June 3, 1901, I found at New Braunfels, Texas, 
on a shady hill that slopes to the lovely sources of the Comal 
River, two medium-sized nests of P/. commutata Mayr. They 
were under stones about sixty feet apart. One contained 
ants of the typical dark variety of the species, while in the 
other nest both workers and soldiers were decidedly paler. 
In either case on lifting the stone my attention was attracted 
by several very large and conspicuous workers, with huge 
abdomens, moving about among the workers and soldiers of 
normal dimensions. I had been collecting and observing the 
1 Wheeler, W. M. Notices Biologiques sur les Fourmis Mexicaines, Ann. 
Soc. Entomol. de Belgique, tome xlv (1901), pp. 199-205. us 
? Emery, C. Remarques sur un Petit Groupe de Pheidole de la Région 
Sonorienne, Bull. Soc. Entomol. de France (année 1901), No. 5, pp- 119-127 
? Forel, A. Fourmis Mexicaines récoltées par M. le prof. W. M- Wheeler, 
Ann, Soc. Entomol. de Belgique, tome xlv (1901), pp. 123-141- 
