1957] 
Weber — Cephalotes atratus 
61 
gynandromorphs by Wheeler, may be female intersexes 
if not also intercastes. These colonies, which are in the 
author’s collection, need to be restudied and the cause or 
causes of the anomalies remain obscure. 
General Environment of the Colony 
The colony was taken on the savannah grounds (eleva- 
tion 63 feet) of the Imperial College of Tropical Agricul- 
ture in a saman tree {Samanea saman ((Jacq.) Merrill) 
of the Family Mimoseae, a large, umbrella-shaped tree 
native to Central America. The daily temperature extremes 
were close to 21-30° C. and annual rainfall some 70 inches. 
The tree was separated by 18 meters of well-cropped 
grassy lawn from the nearest tree, a Cassia grandis, to 
the southwest. The next nearest tree was 48 meters south 
and was a saman which housed a normal Cephalotes 
atratus colony in a large branch. Another tree, a saman, 
was 82 meters southwest from the first and lacked a colony 
of this species. Nine meters south of the latter tree was 
a saman tree with a normal Cephalotes atratus colony. 
There were no other suitable nesting sites in the area. 
It was the habit of the ants of all colonies to forage over 
the grass adjacent to their trees, where some were taken 
by the giant marine toad, long known as Bufo marinus 
(L.) (Weber, 1938). 
The Nesting Tree 
The crown of the saman, fully 30 meters in diameter, 
had an estimated volume of the order of magnitude of 
2000 cubic meters and branches on which the ants were 
found were up to 15 meters distant from the actual nest 
site. The leaves were bipinnate and large and closed just 
before sunset. Early in the dry season (January-May) 
the tree bloomed and late in February young fruiting 
pods appeared. 
Branches of the tree touched those of the Cassia whose 
trunk was 18 meters from that of the saman. The branches 
met at a height of seven meters and served as a bridge 
for the ants. The Cassia , also with large, bipinnate leaves, 
was a young and vigorous tree with smooth bark and 
