DISEASES OF THE COTTON PLANT. 
175 
all the grass oa one side of a field, which was divided into 
two equal parts by a broad and sandy carriage-road passing 
through the centre of it, the grass on the other side having 
been untouched, it was interesting to observe the opera- 
tions of numerous colonies of ants that had formed their 
holes or nests in the road, and were lying in wait for any 
unfortunate grass-wom, the natural desire of which for a 
fresh supply of food should tempt it to cross this danger- 
ous path. First, one ant more vigilant than the rest would 
rush to the attack; then another, and another, until the 
poor caterpillar, entirely covered by its pigmy foes, and 
completely exhausted in strength by its unavailing efforts 
to escape, was finally obliged to succumb to superior num- 
bers and die as quietly as possible, when the carcass was 
immediately carried off by the captors to their nests, or, 
when too heavy "to be dragged away at once, they fed upon 
it as it lay in the road. This warfare was carried on every 
day as long as the grass-worms prevailed, and no doubt 
their numbers were diminished in this way to a consider- 
able extent. 
The grass-caterpillara, when in confinement, very often 
kill and devour each other ; and, when one is maimed in 
the least, it stands a very poor chance for its life. Several 
intelligent planters state that, when the gTass and weeds 
are entirely devoured, and no other vegetable food is to be 
found, they will attack each other and feed upon the still 
living and writhing bodies of their former companions. 
One grass-caterpillar which was kept in confinement, al- 
though furnished with an abundance of green food, actually 
appeared to prefer to feed upon other caterpillars, no mat- 
ter of what kind, so long as their bodies were not defended 
by long, bristling hairs, or spines. 
The grass-caterpillar is from an inch and a half to an 
