THE CAMBERWELL BEAUTY 165 
and as pairing takes place after hibernation, they die without 
depositing. 
Egg Laying. In captivity in this country the eggs are laid 
during April. They are deposited in batches encircling the 
smaller stems of Willow, averaging from 150 to 250 eggs in 
a batch, and the total number laid by one female numbers 
between 450 and 500. 
Egg. The egg is oblong in shape and 0*91 mm. high ; as a 
rule it has eight, but sometimes nine, longitudinal keels, which 
commence just below the summit, where they are much 
elevated. They then gradually decrease in height and dis¬ 
appear before reaching the base; they resemble white frosted, 
fluted glass ; the spaces between the keels are transversely 
ribbed. The base of the egg is firmly embedded in a glutinous 
substance. When first laid, the colour of the egg is rather 
deep ochreous, inclining to olive-yellow, which very gradually 
deepens to an olive-brown to the naked eye ; but under the 
microscope the surface is seen to be finely mottled, resembling 
crocodile skin in pattern, the ground colour being amber- 
brown with light amber reticulations; this pattern lies under 
the shell. When a fortnight old, the colour is a deep lilac-red ; 
and when eighteen days old, is deep leaden-grey.. Just before 
hatching, to the naked eye, the entire batch appears a 
beautiful silver-grey-blue. The egg stage lasts about nine¬ 
teen days. 
Larva. Upon hatching from the egg, the little larva starts 
making its exit by nibbling tiny holes in a circle round the 
crown of the shell ; this continues until it is completely cut 
round ; the larva then pushes the cap off and emerges. It 
immediately starts spinning a carpet of silk as it crawls away, 
spinning as it goes crawling to the extremity of the branch. 
The whole batch of larvae do the same, and at once congre¬ 
gate, forming a colony on the last cluster of leaves, covering 
the bases with web, on which they live and feed in company. 
When fully grown after the fourth moult, the larva measures 
54 mm. long, is of almost uniform thickness, except for the 
first segment, which is very small. The head is bilobed with 
a deep central notch, dull black in colour, and sprinkled with 
warts, each emitting a white hair. The body is covered with 
long shining black spines, which bear a number of fine white 
