Ways and Habis of Caterpillars. 201 
to start marching, which they did one at a time with long intervals between. 
The first one was greatly puzzled on finding the twig broken on which it had 
been reposing. After feeling around for some time it managed at last to find 
one of the twigs on which the broken one rested. Along this it walked 
passing the junction of three other twigs, ascended the stem about a foot, and 
then turned off on to a side twig. Another caterpillar now began to be rest- 
less. It was evident it was secking for the trail of the first, which it soon 
found. He traversed exactly the same path, nor did the broken twig puzzle 
him as long. Eleven others followed, each in going feeling about for the trail 
of its predecessors. By this time it was too dark for me to see the others 
march. How each caterpillar found its way along the exact path of its pre- 
decessor can be explained, it seems, only by asseming some subtle and acute 
sense akin to that of smell. It was not effected by contact or sight, as they 
did not march up in line close to one another but were separated by several 
inches to over a yard. 
Among moths the social habit is exhibited by the green slug-like caterpillars 
of the Limacodid Sibine trimacula, which are common on castor oil, guava, 
hog-plum, coconut, and many other plants, by the “hairy worm ”’ caterpillar— 
white with long dark brown hair—of the Megalopygid Megalopye lanata, which 
frequent guava, mango, ete., by the large greenish red and black-banded cater- 
pillars of our common silk moth the Saturniid Attacus hesperus which live on 
Duranta, cowrida, 2nd a few other plants. In each of these instances the 
caterpilars of the moths merely congregate on their food-plant, but those of 
the Megaloppgid Tolype rivulosa live together in athick tough web, from 
which they issue at nights to feed, to which they return after feeding, and in 
which they pupate. The caterpillars of a Pyralid, a species of Lineodes, 
infest the burre-burra (Solanum sp.), living under a common web. Other 
Pyralid caterpillars which often exhibit sociability are those of Sylepta 
penumbralis, which live on the leaves of the trumpet-tree (Cecropia) and 
those of a species of Desmia, which live on the leaves of Palicourea crocea. 
Many caterpillars, those of the Psychidie, for example, construct cases as 
dwellmgs and protective coverings. These cases are composed of foreign 
materials such as pieces of leaves, bark, twigs, fungi, etc., interwoven with 
silky web. They are more or less cone-shaped, the apex being at the tail- 
end ofthe caterpillars. Through the anterior end the caterpillars may be seen 
to protrude themselves. Very strongly and ingeniously built the structures 
are, and very difficult to tear. Though rough and rugged on the outside, the 
inside is smooth, neat and snug. On examining one of these odd dwellings 
we cannot but marvel when we reflect that its builder had no manufactured 
tools to work with, but had to utilise its feet, jaws, and web. The caterpillars 
never quit their cases, but carry them about with them, and one often feels for 
them bearing such cumbersome things. In spite of such a strong case parasites 
still manage to attack them, as I have bred hymenopterous parasites from more 
than one species. 
Cases are also constructed by caterpillars of certain Tineids, by those, for 
instance, of one of our house-moths. In our houses, in nooks and corners, 
