6 GENERAL ZOOLOGY 



accessory organs, the salivary glands (Fig. 3, 14) and gastric 

 cceca (gastric, pertaining to the stomach ; caeca, pi. of caecum, 

 a pouch or cavity open only at one end, Fig. 3, 1-5, 10). 



The alimentary canal is a long tube extending through the 

 body and variously modified in the course of its extent. The 

 first division is the mouth, guarded on each side by the later- 

 ally moving mandibles. Between the mandibles, and arising 

 from the inner side of the labium, is a short brown, tongue- 

 like organ, the liypopharynx (Fig. 3, 12 ; Fig. 1, 3). At the base 

 of the hypopharynx opens the tube from the several pairs of 

 salivary glands. A portion of the slightly convex surface of 

 the inner side of the labrum is the epipharynx, the seat of the 

 sense of taste. 



Beyond the mouth the alimentary canal continues as a short 

 curved oesophagus (Fig. 3, 13), which leads to a large crop, 

 armed with rows of spine-like teeth. Posterior to the crop 

 is a very small gizzard, also furnished with spines, opening 

 directly into a large, thin-walled stomach (Fig. 3, 17). At the 

 anterior end of the stomach are attached the six tubular 

 gastric cseca, closed at one end but opening into the stomach 

 at the other. Beyond the stomach the alimentary canal con- 

 tinues as a slightly coiled tube, the intestine (Fig. 3, 19), and 

 ends dorsally at the anal opening (Fig. 3, 20). 



The functions of these different parts are as follows, The 

 food, after being crushed by the mandibles and moistened by 

 the saliva, enters the crop, where it is subjected to the action 

 not only of the saliva but also of a fluid from the gastric ceeca. 

 The " molasses " thrown out from the mouth as a defensive 

 fluid by the locust, when handled, consists of partially digested 

 food from the crop, mixed with the digestive fluids. When 

 sufficiently dissolved and changed chemica%, the food filters 

 through the spines of the gizzard into the stomach, where it 

 is further acted upon by another digestive fluid. The thin 

 walls of the stomach allow the particles of prepared food to 



