36 STEUCTURE OF THE LEPIDOPTEEA 



We must now watch the caterpillar through its later days, to 

 see how it prepares for passing into the pupal stage, and to 

 witness the various interesting changes that take place at this 

 period. 



When fully grown, it ceases to eat, and hegins to wander about 

 in search of a convenient spot for the coming event. Its colours 

 fade, and the body becomes appreciably smaller, especially in length, 

 as it ejects the whole contents of its digestive apparatus. Accord- 

 ing to some accounts, it even evacuates the lining of the intestines 

 with their contents. 



A great variety of situations are chosen by the different species 

 at this time. Some will fix themselves on their own food plant, 

 and there remain till they finally emerge in the perfect state, 

 suspending themselves from a silken carpet, hiding themselves 

 in a rolled leaf, or constructing a cocoon of some kind. A large 

 number walk down the food plants, and undergo their changes 

 in moss that happens to lie at the foot ; or construct a cocoon 

 on the surface of the ground, utilising for the purpose any decayed 

 leaves, fragments of vegetable matter, or pieces of earth or small 

 stones. Many seek a further protection than this, and burrow 

 into the soil, where they either lie in a little oval cell that they pre- 

 pare, or in a cocoon constructed by spinning together some particles 

 of earth. Again, there are those caterpillars, chiefly of butterflies 

 that frequent our gardens, which find their way to the nearest wall 

 or fence, and there secure themselves in a sheltered nook. We 

 will watch a few of these varied methods of procedure, taking as 

 our first instance the caterpillar of the common Large White or 

 Cabbage Butterfly. 



When fully fed, this larva seeks out a sheltered spot, generally 

 selecting the under surface of some object, or of the ledge of a 

 wall or fence. Sometimes it will not even leave its food plant, 

 though it generaUy walks some considerable distance before a suit- 

 able shelter is found. Having satisfied itself as to the site of the 

 temporary abode, it sets to work at spinning a silken carpet. At 

 first the threads spread over a rather wide area, and seem to be 

 laid in a somewhat irregular and aimless manner ; but after a little 

 time its labours are concentrated on one small spot, where it spins 

 several layers of silk fibres. 



This done, it fixes the little hooks of the claspers firmly in its 

 carpet bed, and then proceeds with a highly interesting movement. 

 It is not satisfied with only the one mode of suspension. In fact, 



