THE INTERNAL ANATOMY OF INSECTS 107 



III. THE ALIMENTARY CANAL AND ITS APPENDAGES 



a. 



THE MORE GENERAL FEATURES 



The alimentary canal is a tube extending from one end of the body- 

 to the other. In some larvse, its length is about the same as that of 

 the body; in this case it extends in a nearly straight line, occupying 



Fig. 124. — Internal anatomy of a cockroach, Periplaneta orientalis; a, antennae; 

 ^i, 62, 63, first, second, and third legs; c, cerci; d, ventricular ganglion; e, 

 salivary duct; /, salivary bladder; g, gizzard or proventriculus; h, hepatic 

 coeca; i, mid-intestine; j, Malpighian vessels; k, small intestine; /, large 

 intestine: m, rectum; n, first abdominal ganglion; o, ovary; p, sebaceous 

 glands (From RoUeston). 



