422 
ANNUAL REPORT OF NEW-YORK 
uals who are every moment returning there from feeding. 
Having taken this journey to the end of the limb and back and 
thus had the amount of exercise which they require, they crawl 
into the tent and there compose themselves to rest. Thus when 
but a few straggling worms remain upon the limb on which 
they have all been feeding, a few others will be seen journeying 
homeward to the tent, a multitude of others will be seen walk¬ 
ing about upon the surface of the tent spinning their threads, 
many more will be seen traveling upon both of the branches 
which fork off from the tent, some of them going out and others 
coming in, whilst the inside of the tent is black with the multi¬ 
tude that has completed their labors and retired to repose. The 
ranks of each of the sections first specified gradually become 
thinner, until at last all have withdrawn into the tent. 
Dr. Harris (Injurious insects, 2d ed. p. 287) says these cater¬ 
pillars “all retire at once when their regular meals are finished;” 
and it must hence be inferred from his account that it is after 
reposing and before going out to feed that they strengthen their 
nests with additional threads. But from repeated observations 
I am assured that it is after feeding and before retiring to rest 
that they add the new threads to their nests. The routine in 
which they pass their lives consists of the three acts, feeding, 
exercising, and resting. Dr. H. also says that “At all times 
when not engaged in eating, they remain concealed under the 
shelter of their tents.” But upon warm days when the sky is 
serene, they do not retire into their tent at all, but repose upon 
its outside, which is literally covered with them, and so black 
that at first sight persons suppose the nest to be a black hat 
placed in the tree. They are very sensitive to atmospheric 
changes. Upon rainy days they remain within their tents and do 
not go out to feed; yet I have repeatedly seen them feeding at 
night when the leaves were wet with dew, and still oftener in 
the morning before this moisture had evaporated. On the eighth 
of May, the worms on a bush which I had taken into my study, 
went out of their nest to feed in the morning; but it coming on 
to rain out of doors, they all quickly returned into the nest. 
I hereupon kindled a fire in the stove and the warmth had no 
sooner commenced diffusing itself through the room than these 
