Alimentary System of Gryllotaljm australis. 119 



Lateral to these again are two smaller projections with 

 depressed summits, the centre of which marks the lateral 

 extremity of one-sixth part of the whole ridge, and from 

 whence, on each side, commence similar parts of the same 

 radial ridge. These lateral projections are not transversely- 

 divided, but run uninterruptedly from the anterior to the 

 posterior extremity of the columns (Figs. 4 and 6, P.). 



It must be remembered that the whole of the inner cuticle of 

 the gizzard is strongly chitinous. 



The anterior eleven or twelve transverse ridges (they vary in 

 number) in the main agree with the foregoing description, and 

 occupy a distance conjointly of 2 mm. Considered as a whole 

 in relation to their shape, position, and the muscle fibres, one is 

 justified in considering these teeth as capable of mastication to 

 some extent, and this is achieved, I believe, by the lateral faces 

 of the teeth of the central fold working against similar teeth in 

 the next parts of the ridge on each side, and so incision and 

 crushing is brought about. Further, owing to their shape, and 

 also to the aid of the setaceous projections, briefly mentioned, 

 the finely triturated food is separated from coarse material, which 

 is kept in the centre of the organ, and conveyed to longitudinal 

 channels which run along the radial wall between the lateral 

 folds, and become more pronounced towards the posterior. 

 These I call food-pulp channels (Figs 3 and 6, F.P.O.). 



A transverse section, taken a little below the chitinous teeth, 

 at the part marked 4 in Fig. 3, is shown in Fig. 6, the ridges 

 of the six longitudinal columns, previously considered, will be 

 seen to have changed in structure, they have no strong chitinous 

 teeth, but the folds are covered by thin cuticle, clothed with fine 

 setse. The parts are not all alike, two, side by side, are similar 

 to other two that are diametrically opposite, while the remaining 

 two are quite different, but each is like the other, and they are 

 situated opposite to each other. The food-pulp channels are here 

 very conspicuous, and are seen to be guarded by projections and 

 flaps, clothed with setaj, which act as guards to prevent the 

 marc, or coarse food residue, which is kept in the centre of 

 the gizzard, from gaining entrance to them. Tracing these 

 food-pulp channels to the posterior outlet they are found to 



