THE ALIMENTARY CANAL 



28l 



mandibles, and is frequently lined with rows of horny 

 teeth, which are specially developed in grasshoppers, 

 crickets, and locusts. The intestines are remarkable 



: a\ 



FIG. 239. Alimentary canal of a Beetle: FIG. 240. Alimentary Canal of the Bee 



a, pharynx; b, gullet, leading to crop, (Apis mellifica}\ a, gullet; b, crop; c, d, 



c, gizzard, d, and stomach, e; f, deli- stomach; e, small intestine; f, large in- 



cate urinary tubes; g s intestine; h, testine; g, anal orifice; /*, urinary vessels; 



other secreting organs. /, auxiliary glands. 



for their convolutions. Insects have no true liver ; but 

 its functions are performed by little cell masses on the 

 inside of the stomach. 93 



FIG. 241. Anatomy of a Sphinx Moth; , nervous cord; ', brain sending ofT nerves 

 to the legs, /', I" , /'", and for the wings at "; h, dorsal vessel, or heart; c, crop; 

 s, stomach; i t intestines; o, reproductive organs; o' , oviduct; 8-20, segments. 



The alimentary canal of spiders is short and straight, 

 the pharynx and gullet being very minute. The stom- 



