DIGESTIVE POWERS OF INSECTS. 



197 



The wide and glandular crop (a) passes the food into a compara- 

 tively small stomach (h c\ and the liver (d) consists of a few 

 simple biliary ducts. All this corresponds with their easily diges- 

 tible food, while in the vegetable-eating insect the alimentary 

 canal is more lengthened, convoluted, and capacious, with 

 numerous dilatations, and the glandular organs are more 

 developed in order to subdue the resistance of more re- 

 fractory aliments. Thus in the cockchafer the stomach (6) is 

 extremely long ; the intestine has several enlargements or sup- 

 plementary stomachs, as they 

 might be called, for extract- 

 ing every nutritious particle 

 from the tough leaves on 

 which this destructive beetle 

 subsists ; and the liver (c c\ 

 which is here of great mag- 

 nitude, has its secreting sur- 

 face much extended by the 

 development of innumerable 

 minute casca from its pri- 

 mary ducts. 



In the class of insects we 

 find all the various modes of 

 motion united that are but 

 partially scattered among 

 other animals. They walk, 

 they run, they jump, they 

 climb, dig, and burrow 

 with the quadrupeds; they 

 rival the birds in rapidity of 

 flight, they glide along with 



Alimentary Canal of the vegetable -eating 



the agility of serpents, and Cockchafer. 



the fishes are not more perfect swimmers ; so that it may be 

 said without exaggeration that these restless little creatures, 

 formed alike for the earth, the waters, and the air, give life to 

 every portion of our globe, The construction of their feet 

 corresponds in an admirable manner with their various 

 modes of motion, so that a mere glance at an insect's legs 

 suffice to give us an idea of its way of life. Thus the exces- 

 sively strong forelegs of the mole-cricket, with their broad 



