DIGESTIVE ORGANS OF INSECTS. 



217 



especially while it is undergoing its different 

 metamorphoses. 



These changes are most conspicuous in the 

 Lepidoptera, where we may observe the suc- 

 cessive contractions which take place in the im- 

 mensely voluminous stomach of the caterpillar, 

 while passing into the state of chrysalis, and 

 thence into that of the perfect insect, in which 

 its form is so changed that it can hardly be 

 recognised as the same organ. I have oiven re- 



328 



presentations of these three different states of 

 the entire alimentary canal of the Sphinx ligustri. 



