INSECTS 



tubular part, the small intestine (SInt), and of a great 

 terminal receptacle, the rectum {Reef), filled with a mass 

 of soft orange-colored matter. In the fully-matured insect 

 (C), after it has escaped from the cocoon, still further 



Fig. 164. Transformation in the form of the alimentary canal 



of the tent caterpillar from the larva to the adult moth 

 A, alimentary canal of the caterpillar. B, the same of the pupa. 



C, the same of the moth 



O, crop; /»/, intestine; Mai, Malpighian tubules (not shown full 



length); Oe, oesophagus; Reel, rectum; SInt, small intestine; Vent, 



ventriculus 



alterations have taken place. The crop sac [Cr) is now 

 greatly distended into a spherical vesicle tensely filled 

 with gas — air, probably, that the moth has swallowed, 

 perhaps to aid it in breaking the pupal shell, for there are 

 sometimes small bubbles also in the tubular oesophagus. 



[3 IO J 



