THE AUSTRALIAN NAYURALIST. 201 
ing foe, or it can crawl away from danger. But a pupa 
is quite helpless in itself, and every caterpillar, in one 
way or another, makes provision for its protection dur- 
ing this quiescent transforming period. Some seek the 
soft soil in which to hide their weakness, and others spin 
silken wrappings to guard them from the cold; wet, and 
hungry birds, and this tissue envelope is a cocoon. 
When fully grown the caterpillar turns aside from its 
former one occupation (eating) and thinks about protect- 
ing itself for its changing pupal state. It does not look 
like the vigorous creature it had been whilst thriving on 
leaf pulp. Generally it loses its bright coloration, and 
shrinks in size, just ere it begins to spin. It spins by 
means of spinnerets in the lower lip, and to and fro, hither 
and thither, the tireless head moves unceasingly, cris- 
crossing the strands until it is entirely encased in a web 
of silk, secure and firm to protect the pupal change. 
The cocoon is not only pure silk mesh, for it has 
mixed with it fat, wax, gum, pigment, ete. Only about 50 
per cent. is pure silk. The silk issues in a thin, quickly 
hardening, liquid stream. 
1. Cocoon and enclosed pupa of a moth, Genus Vert. 
This caterpillar makes a cylinder-shaped cocoon of a light 
wrapping of silk, shooting out loosely among the mesh the 
hairs upon its body, which had been its protection in its 
larval state. 
2. Caterpillar, cocoon, and a moth, Anthela censors. 
This woolly bear caterpillar encloses itself in an outer en- 
yelope of loose silk, surrounding a very thickly-felted cell, 
and moreover, to protect itself further it spins the cocoon 
between the scaly bark and the tree trunk. 
3. Cocoon of Hntometa fervens, with pupa within. 
This is very like the cocoon of the Indian silkworm moth ; 
it is very closely spun, giving it a beautifully finished 
appearance. It is quite a hard cell, and the green colora- 
tion is a perfect example of protective mimicry. 
4. Cocoon and moth cf Australian silkworm moth, 
Antheraeca cucalypli. We had very many of these insects 
brought in, and all had big appetites. Only one was at- 
