62 



INSECT TRANSFORMATION 



evident after the caterpillar has moulted for the last time. In 

 preparation for this process of pupation, the insect spins a 

 quantity of silk, greater if, as in the case of many moths a 

 complete cocoon is provided for the covering of the body, less 

 if, as with most butterflies, a 'pad for the suspension of the 



FIG. 34. 



a, b, c, d, Sections showing successive stages in the development of the 

 wing-bud of Butterfly (Pirn's) ; e, skin; ct, cuticle; d, wing-bud; 

 p, pouch ; t, air tubes, x 100. e, f, surface views of buds, fore- and 

 hind-wings in last larval stage, showing tracheation. x 12. From 

 Comstock after Mercer, Journ. N.Y. Ent. Soc. VIII. 



