THE SAUBA ANT 
75 
giving the preference to cultivated trees, such as the orange 
and the coffee, and cut away the leaves so fast that the growth 
is stopped, and the entire plant sometimes dies. 
The use of the leaves is to thatch the domes of their curious 
edifices, and to prevent the loose earth from falling in. Some of 
these domes are of gigantic dimensions, measuring two feet in 
height and forty feet in diameter, the mightiest efforts of man 
appearing small and insignificant when the comparative dimen- 
sions of the builders are taken into consideration. Division of 
labour is carried out to a wonderful extent in these buildings, 
for the labourers which gather and fetch the leaves do not place 
them, but merely fling them down on the ground, and leave 
them to a relay of workers, who lay them in their proper order. 
As soon as they have been properly arranged, they are covered 
with little globules of earth, and in a very short time they are 
quite hidden by their earthy covering. 
The functions performed by the large-headed ants are not very 
evident. Those with smooth fronts seem to do nothing but walk 
about. They do not fight like the soldier-termites, nor do they 
appear to exercise any rule over the workers. Moreover, they 
have no sting, and even when assaulted they scarcely ever resent 
the insult. The hairy-headed variety is still more enigmatical 
in its duties. 4 If the top of a small, fresh hillock, one in which 
the thatching process is going on, be taken off, a broad cylin- 
drical shaft is disclosed, at a depth of about two feet from the 
surface. If this be probed with a stick, which may be done to 
the extent of three or four feet without touching the bottom, a 
small number of colossal fellows will slowly begin to make 
their way up the smooth sides of the mine. Their heads are of 
the same size as the class No. 2, but the front is clothed with 
hairs instead of being polished, and they have in the middle of 
the forehead a twin ocellus, or simple eye, of quite different 
structure from the ordinary compound eyes on the sides of the 
head. This frontal eye is totally wanting in the other workers, 
and is not known in any other kind of ant. The apparition of 
these strange creatures from the enormous depths of the mine 
reminded me, when I first observed them, of the Cyclopes of 
