%8 COMPARATIVE ZOOLOGY. 
sects having mandibles, and is frequently lined with rows 
of horny teeth, which are specially developed in Grass- 
Fra. 39.—Alimentary Canal of a Beetle: Fre. 40.— Alimentary Canal of the Bee 
a, pharynx ; 0, gullet, leading to crop, (Apis mellifica): a, gullet; b, crop; e, d, 
¢, gizzard, ¢, and stomach, e; J, deli- stomach; e, small intestine; f, large in- 
cate biliary tubes; g, intestine; h, testine; g, anal orifice; h, biliary ves- 
other secreting organs. sels; 7, auxiliary glands. 
“ hoppers, Crickets, and Locusts. The intestines are re- 
markable for their convolutions. Insects have no true 
liver; but its functions are performed by little tubes 
(ceca) around the stomach.” 
The alimentary canal of Spiders is short and straight, 
the pharynx and gullet being very minute. The stomach 
is characterized by sending out tubular prolongations, and 
the intestine ends in a large bladder-like expansion. Scor- 
n’ n' 
4 
n uowoye rege a oe 
Fig. 41.—Anatomy of a Sphinx Moth: 7, nervons cord; 7’, brain sending off nerves to 
the legs, U,V’, U’’’, and for the wings at n’’; h, dorsal vessel, or heart; ¢, crop; 8, 
stomach; 7, intestines; 0, reproductive organs; 0’, oviduct ; 8-20, segments. 
