360 ANIMALS OF NEIGHBOURHOOD OF EGA. Cuap. XII. 
was visible. All were moving in one and the same direction, except a 
few individuals on the outside of the column, which were running 
rearward, trotting along for a short distance, and then turning again to 
follow the same course as the main body. But these rearward move- 
ments were going on continually from one end to the other of the line, 
and there was every appearance of this being a means of keeping up a 
common understanding amongst all the members of the army, for the 
retrograding ants stopped very often for a moment to touch one or 
other of their onward-moving comrades with their antennez ; a proceeding 
which has been noticed in other ants, and supposed to be their mode of 
conveying intelligence. When I interfered with the column or ab- 
stracted an individual from it, news of the disturbance was very quickly 
communicated to a distance of several yards towards the rear, and the 
column at that point commenced retreating. All the small-headed 
workers carried in their jaws a little cluster of white maggots, which I 
thought at the time might be young larvee of their own colony, but after- 
wards found reason to conclude were the grubs of some other species, 
whose nests they had been plundering, the procession being most likely 
not a migration, but a column on a marauding expedition. 
The position of the large-headed individuals in the marching column 
was rather curious. There was one of these extraordinary fellows to 
about a score of the smaller class: none of them carried anything in 
their mouths, but all trotted along empty-handed and outside the column, 
at pretty regular intervals from each other, like subaltern officers in a 
marching regiment of soldiers. It was easy to be tolerably exact in this 
observation, for their shining white heads made them very conspicuous 
amongst the rest, bobbing up and down as the column passed over the 
inequalities of the road. I did not see them change their position or 
take any notice of their small-headed comrades marching in the column, 
and when I disturbed the line they did not prance forth or show fight 
so eagerly as the others. These large-headed members of the com- 
munity have been considered by some authors as a soldier class, like 
the similarly-armed caste in Termites ; but I found no proof of this, at 
least in the present species, as they always seemed to be rather less 
pugnacious than the worker-minors, and their distorted jaws disabled 
them from fastening on a plane surface like the skin of an attacking 
animal. I am inclined, however, to think that they may act, in a less 
direct way, as protectors of the community, namely, as indigestible 
morsels to the flocks of ant-thrushes which follow the marching columns 
of these Ecitons, and are the most formidable enemies of the species. 
It is possible that the hooked and twisted jaws of the large-headed class 
may be effective weapons of annoyance when in the gizzards or stomachs 
of these birds, but I unfortunately omitted to ascertain whether this was 
really the fact. q 
The life of these Ecitons is not all work, for I frequently saw them 
very leisurely employed in a way that looked like recreation. When 
this happened, the place was always a sunny nook in the forest. The 
main column of the army and the branch columns, at these times, were 
in their ordinary relative positions; but instead of pressing forward 
eagerly, and plundering right and left, they seemed to have been all 
