1940] 
Caste Determination in Ants 
111 
pating curves of colony B). Thus the queen larvae are en- 
abled to grow to normal size at normal rate even though the 
colony is on reduced rations, A similar pattern, in reverse, 
could hold for those species in which the queens .are pro- 
duced in late Summer or Fall. 
Summary 
An experiment is described which indicates that the fe- 
male castes of Leptothorax curvispinosus are determined 
trophogenetically and not blastogenetically. 
Literature Cited 
Ezhikov, T. Individual variability and dimorphism of social insects. 
American Naturalist, 68 pp. 333-344. 1934. 
Wheeler, W. M. Mosaics and other anomalies among ants. Harvard 
Univ. Press. 1937. 
Whiting, P. W. Anomalies and caste determination in ants. Journ. 
Hered., 29 pp. 189-193. 1938. 
