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. × 75.

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 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 cæcal tubes. Between the wall of the gizzard-tube and its external reflected layer, tracheal tubes, fat-cells, and longitudinal muscles are enclosed.

Fig. 64.—Longitudinal section through Giz­zard and fore-part of Chyl­ific Stom­ach. G, giz­zard; Tu, cæc­al tube; St, stom­ach; Ep, its lin­ing epi­the­lium. A and B are en­larged in the side fig­ures. × 35.

A.—The Reflected Chitinogenous Layer of the Tubular Gizzard. Tr, tracheal tube. × 400.

B.—One of the Tubular Extensions of the same, enclosing muscles and tracheæ. × 400.