90 
TRANSFORMA TIONS OF INSECTS. 
throws back its head, and twists it sideways, so as to touch 
the wood on one side of the body. The touch pulls out a 
silken thread, and then the insect carries the head to the other 
side, and fixes the silk. This is repeated several times, until a 
sort of sling is placed over the body. Then the first metamor- 
phosis takes place, and the chrysalis finds itself slung by the 
tail, and girded to the wood-work by a silken sling. 
The first step to cocoon making, which is so usual in the 
next division of the Lepidoplera , is shown in the habit that 
CATERPILLARS OF THE CABBAGE BUTTERFLY SLINGING THEMSELVES BEFORE THE 
FIRST METAMORPHOSIS. 
Pamphila aracynthus has of swathing itself with a network of 
silk before undergoing the first metamorphosis, and the leaf- 
rolling propensities of many caterpillars and moths are fore- 
shadowed by a species of Syrichtus. 
The angular shape of the butterfly chrysalides may have 
something to do with their comparatively unprotected and 
uncovered state, for this sharpness of outline which causes 
them to differ in appearance from most living things is not so 
perfectly seen in the case of the Anthocharis , from Spain, which 
spins a slight cocoon. 
It has already been stated that the repeated sheddings of the 
skin and mucous (epithelial) tissues of the caterpillars during 
