BOMBYCIDS. 
103 
ig creature with large coral-red tubercles on the forward part of its 
idy, yellow ones on its back, and smaller blue ones on its sides and 
about its head, all covered with short black bristles. It clasps the 
hough or twig on which it rests with a wonderful tenacity, and if 
iaced on one’s finger the grasp of its fleshy feet with their minute 
tooks is very noticeable. It has a peculiar odor, both in the larva 
id the moth state, which may be of some protection to the animal. 
Toward the end of September the caterpillar constructs its coarse, 
rown, elongated cocoon, which is usually attached on one side to a 
vig or branch. This cocoon is composed of two parts, consisting of 
loose, wrinkled outer covering and a well-shaped and dense inner 
od, with fine floss silk separating the two, which are both loosely 
Section of cocoon of Attacus cecropia. 
pun at one end to enable the moth to make its escape. There is 
■equently a marked difference between the cocoons found on trees 
nd shrubs on high ground and those taken from low bushes and 
shrubs in swampy districts. The latter are frequently two or three 
mes as large externally as the upland variety, and have a large 
mount of the floss silk between the outer and inner coverings, 
'his variation I cannot explain, and have noticed no difference in 
i le moths emerging from the two varieties of cocoons other than 
•oat the swamp-inhabiting specimens appear larger and richer in 
oloring than their upland relations. Sometimes the cocoons of these 
oecies are to be found in large numbers. In the suburbs of Chicago 
f hey may be seen on the shade trees in dozens and sometimes in liun- 
reds ; and I have known two men to collect a bushel of them in 
