16 
Psyche 
[March 
From the onset this line of reasoning appears weak, 
since it is obvious that the environment of the ovary is by 
no means the only condition affecting individual develop- 
ment which is common to all ant colonies. Colonial organi- 
zation and the details of individual postembryonic develop- 
ment are fundamentally the same for all ants and are 
amenable to the establishment of any number of physio- 
logical mechanisms controlling caste differentiation. To 
settle on one specific mechanism without supporting evi- 
dence is to engage in almost pure speculation. Since a great 
deal of new information bearing on this subject has been 
brought to light in the past decade, a reevaluation of 
Flanders’ suggestions and of the literature pertinent to 
them is warranted at the present time. 
One does not need to look far to find that Flanders’ 
hypothesis is contravened by a considerable body of evi- 
dence, much of it resting in the literature. While it is pos- 
sible that the differences in yolk content which are pre- 
sumed to underlie caste differentiation may be so subtle 
as to escape the eye of the casual myrmecological observer, 
it still should be taken as significant that variation in egg 
size and content have rarely been recorded in the liter- 
ature and then have been shown definitely not to correlate 
with caste differentiation (Eidmann 1931, Ledoux 1950). 
Some effort has actually been made to demonstrate caste 
differences at the level of the egg, as in the work of Bhat- 
tacharya (1943) on Oecophylla smaragdina (Fabricius), 
but with negative results. Direct evidence against the 
hypothesis may be supplied by the work of Ledoux (1949, 
1950) on Oecophylla longinoda (Latreille). In this species 
the workers act as supplementary reproductives and can 
produce males, queens, and major and minor workers with 
equal facility. Two sizes of eggs are laid, averaging in 
length 0.6 mm and 1.1 mm respectively. The larger size 
yields males, the smaller, any of the three female castes. 
The fecundated female, on the other hand, lays eggs all of 
the same size, averaging 1.2 mm in length, from which 
proceed either workers (at least) or males. Ledoux has 
offered the logical explanation that the smaller worker 
eggs produce females and not males, as would be expected 
