No. 403.] ECITON SUMICHRASTI NORTON. 567 
The differences between 24 and 97 seem to be due to a 
difference in age, the former being a young queen,— possibly 
not more than a year old, — the latter a much older individual. 
If this supposition is cor- 
rect, and if the differences 
above noted are constant, 
it is probable that the ? 
Eciton exhibits a certain 
amount of postmetamor- 
ia 
[132 - 
2 4 
phic growth even in the ff : m ^W 
thoracic and basal abdom- ,.« IR T 
inal regions. (Re ae NESS 
The similarity of the 9 
Eciton tothe African Dich- 
thadia, the reputed female a 
of Dorylus, will be appar- Nessie 
ent to any one who com- 
pares the accompanying 
figures with Emery’s figure 
of Dichthadia.! I also give 
a figure (Fig. 1) of the 
worker of E. sumichrasti 
for the sake of showing 
the remarkable differences 
between the fertile and 
sterile forms of the same 
sex. The single node in 
the abdominal pedicel of 
the female and the two Fic. 3.—Old fertile female, or queen, of Eciton sumi- 
nodes in the worker, char- ^r 'uedawhgospdbe 5 
acters which are often used 
in the taxonomic separation of whole families of ants, are here 
combined, not only in the same species, but in the same sex P 
! Reproduced in Sharp's contribution to the Cambridge Natural History, 
vol. vi, p. 178, Fig. 79. 
2 The discovery of a single node in the pedicel of the female Eciton strengthens 
the already strong probability that Labidus, also with a single node, is the dona 
Jide male of this genus. 
