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TEXTBOOK OF ZOOLOGY 



central portion of the body. The food after being ground up by the 

 mouth parts passes into the mouth or pharynx where it is mixed 

 with the salivary mucin and the action of the enzyme, invertase, 

 begins. From the mouth the food is conveyed through the esopha- 



— \-/A 



's-.e./ 



5t. 



-A\.X 



H'lnt. 



n 



-to. 



-■R;. 



J.A 



Fig. 202. — Digestive system of Rhomaelia microptera. A, anus; O, crop; Co., 

 colon ; G.C., gastric caeca ; Int., intestine ; M, mouth ; M.T., Malpighian tubules ; 

 Oe., esophagus; R. rectum; Sal., salivary glands. (From White, General Biology. 

 The C. V. Mosby Co.) 



