THE BOMBYCTNA. 
1 1 I 
especially strong and membranous, in order that it can grasp 
the twigs safely. 
The emperor moth has a very pretty larva, which is often 
found upon heather in the summer. It is green, and each 
segment has seven pink tubercles on black rings, and each 
tubercle has a tuft of short black hair. The spiracles are 
orange in colour. 
The caterpillars of A ttacus cecropia, from Louisiana, are 
remarkable for the changes they undergo in moulting, before 
transforming themselves into pupae. 
At their birth they are almost black, and are decorated with 
verticillate hairs, which make them look like little hedgehogs. 
After a few days their general colour becomes clearer and lighter, 
and the tubercles which support the hairs become more promi- 
nent. The skin is then moulted, and the new one succeeds, and 
is of a grey green or russet colour, and all the tubercles and spines 
are brilliantly black. Moulting again occurs, and, behold, a light 
green creature appears, with five rows of black spots ; two mag- 
nificent tubercles of a carmine colour are to be observed on the 
second and third segments, and two of a light yellow are situated 
upon the dorsal part of every other segment. Each tubercle 
carries several verticillate hairs, which are black. A third moult 
finds the body becoming an azure blue on the back, with black 
spots on the sides and head ; the tubercles form two rows on the 
back, and are much enlarged ; they are red in colour, and the other 
tubercles have a single spine upon them. Finally the last moult 
takes place, and the caterpillar turns out to be of a pale green 
colour, with all the lateral tubercles of a light green, and the red 
tubercles have taken on an orange tint, and have only one spine. 
These changes of colour and of the development of tubercles 
and hairs during the skin-shedding are indeed most remarkable. 
The Cocoons of these caterpillars are double. There is an 
envelope, hard, and like parchment in its texture, which can readily 
be separated from the inner and silky one. 
An A ttacus , whose moth, larvae, and cocoon are represented in 
the engraving, is called Attacus lima , and is celebrated for the 
fine silk of its caterpillar, which feeds especially upon the Liquid- 
ambar trees of Carolina and Florida. 
