THE ALIMENTARY CANAL AND ITS APPENDAGES. 



119 



The gizzard ends below, as we have already mentioned, in a 

 narrow cylindrical tube which is protruded into the chylific 

 stomach for about one-third of an inch. Folds project from the 

 wall of this tube, and reduce its central cavity to an irregular 

 star-like figure. Below it ends in free processes slightly 

 different from each other in size and shape. The chitinous 



ci tn 



P 



Fig. 62. Section through one tooth and two intermediate spaces (see figure 61, 

 A A). Cc, chitinous cuticle; C, chitinogenous layer; am, annular muscles; 

 p, peritoneal layer. X 75. 



Cc 



Fig. 63. Section through one principal hairy ridge and two intermediate spaces 

 (see fig. 61, B B) ; rm, radiating muscles ; tr, trachea. The other references 

 as before. X 75. 



lining and the chitinogenous layer beneath pass to the end of 

 the tube and are then reflected upon its outer wall, ascending 

 till they meet the lining epithelium of the caecal tubes. Between 

 the wall of the gizzard-tube and its external reflected layer, 

 tracheal tubes, fat-cells, and longitudinal muscles are enclosed. 



