126 NEW ZEALAND NATURE-STUDY BOOK 
at first but rapidly grows in size, consuming large quantities 
of food, and sometimes reaching upwards of three inches in 
length. During the process of growth its skin becomes too 
small and is cast. This casting of the skin is characteristic 
of all larvee—in the case of the Silk-worm four new skins are 
Fig. 84.—Silkworm Moth (female) 
} 
SS Seen 
ye a, 
Me. 4 
ed 
d! MS, ae 
“iy “0 
a ave 
Wy 
Fig. 85.—Silkworm Moth (male). 
formed and as many old ones cast during the larval stage, 
which lasts from six to eight weeks. Pupils will notice the 
form of the larva. Its head is small, hard, and reddish- 
black in colour. Its body is light grey, and made up, to 
all appearance, of twelve segments (there are really thirteen, 
but the last is only obscurely indicated), of which the last 
