AND THE LOWER ANIMALS. 61 



cliece, or air- tubes, which extend almost to their extre- 

 mities. Moreover they are covered by two exquisitely 

 delicate transparent membranes, which, firmly united 

 together, clothe the upper and under surfaces. It is 

 to these that the little scales are attached which give 

 the peculiar colours to this and other butterflies, being 

 implanted in the membrane somewhat in the same 

 manner as a bird's feathers are implanted in its skin. 

 The caterpillar did not present the slightest trace of 

 these wings or their appendages. 



The abdomen, which corresponds to the hinder 

 portion of the caterpillar's body, has lost all its false 

 feet, but with that exception has undergone very little 

 alteration. The general form has been slightly modi- 

 fied, the colour is no longer the same, but the abdo- 

 men is invariably divided into seven rather distinct 

 rings. 



Before proceeding any further, we must state, what 

 it is of some importance to bear in mind : viz., that 

 these moultings, metamorphoses, and alterations, 

 although apparently occurring spasmodically, do not 

 do so in reality. Beneath the veil of skin, which will 

 be thrown off in course of time, even within those 

 parts which will eventually disappear or be transformed 

 into others, the new integument is being gradually 

 formed ; the general plan of the future animal is being 

 drawn out, and the various organs which will after- 

 wards be required are being organized. The old gar- 

 ment alone is cast off, both at the period of moulting 

 and of metamorphosis. If we cautiously detach the 

 old but still vital skin, a few days before the moulting 

 takes place, we may see its successor lying beneath 

 it. By doing the same with the caterpillar, a few 



