322 



LEPIDOPTERA 



transparent scale of somewhat inconstant ontline. Some are 

 coloured and mottled somewhat after the fashion of birds'-eggs ; 

 this is the case with some eggs of Lasiocampidae and Liparidae ; in 

 some the sculpture of the egg-shell is of the most elaborate char- 

 acter (Figs. 77, 78, Vol. v.). The egg-shell or chorion is, accord- 

 ing to Korschelt ^ and others, a cuticular product of the epithelium 

 of the egg-chambers of the ovaries. Tlie number of eggs deposited 

 by an individual differs greatly in different species, and has been 

 ascertained to be variable within certain limits in the same 

 species. Speyer thought about 250 to be the average number 

 of eggs deposited by an individual. The number in the case of 

 Ajjuria crataegi is believed to be from 60 to 100, and in some 

 Sepialus to be several thousands. The mode of deposition also 

 differs greatly ; where the eggs are very 

 numerous they seem to be discharged almost 

 at random in suitable spots ; but moths such 

 as Clisiocampa neustria fasten their eggs 

 round the stems of the food-plant in a very 

 perfect and artistic manner. Butterflies 

 seem as a rule to prefer to oviposit by placing 

 an egg here and there rather than risk many 

 in one situation ; but to this there are many 

 conspicuous exceptions especially in the cases' 

 where the larvae live gregariously, as in the 

 Yanessae. Some moths cover the eggs with 

 .^.-,,, fur from their own body, which, in the case 

 of certain of the Eggers (Lasiocampidae), 

 seems to have a special supply for the pur- 

 pose. The period that intervenes between 

 deposition and hatching of the eggs varies 

 from a few days to many months. There 

 seems to be, as a rule, comparatively little power of extending the 

 period of latency beyond a single season ; though certain facts 

 have been recorded that would lead us to believe that in 

 Australia eggs may last over the proper time during a drought, 

 and be hatched as soon as rain falls. 



Larva. — The young condition or larva of the Lepidopterous 

 Insect is commonly called a caterpillar. It is a somewhat 

 worm-like creature — in old English it was sometimes called 



' Acta Ac. German, li. 1887, p. 238. 



Fig. 164. — Egg of Orange- 

 tip buttertly, Euchloe 

 cardamines, magui- 

 fied. a, The egg of 

 natural size on a stalk. 



