116 Proceedings of the Royal Society of Victoria. 



compressed, and terminate at the summit in one or more fine 

 points. They are acutely bent at their base, and point back- 

 wards, so that they overlap one another like tiles on a roof. 



Crop. 



The crop or ingluvies, into which the fore-gullet opens, is a 

 large ellipsoidal thin-walled sac, situated in the thorax. When 

 fully distended it measures about 6 or 7 mm. at its widest 

 diameter. In contrast to other of the Orthoptera it is situated 

 on one side of the axis of the digestive tube. It may be con- 

 sidered as a large lateral expansion of a part of the wall of the 

 oesophagus, the opposite portion of the wall continuing postei'iorly 

 for about -5 mm., when it is met by the return of the wall of the 

 crop to form the posterior outlet of that organ. 



The histological elements are the same in kind as those of the 

 oesophagus. In contra-distinction, its wall is much thicker, due 

 in part to the epithelial cells which are columnar shaped, and 

 also to the cuticle, which is thicker. The musculature is similar, 

 viz., thin bands of muscle fibres crossing one another. The teeth 

 are much shorter, each terminating in a point, and they project 

 inwards like teeth of a saw, and are arranged to form rows side 

 by side in close juxtaposition. The surface thus presents an 

 appearance something like a rasp. 



When the crop is not fully distended by food the epithelial 

 and chitinogenous layers are thrown into deep corrugations, 

 which radiate from the openings, and when further emptied the 

 whole wall is deeply folded, and the organ presents a much 

 shrivelled appearance. 



Both at the anterior ojaening and posterior outlet the annular 

 muscles of the gullet are much more numerous, and valves are 

 formed by cushions on the inner wail. If inflated with air and 

 then dissected out, I have found that only a small quantity of 

 air escapes, the organ remaining considerably distended, which 

 demonstrates how effectually the inlet and outlet may be closed. 



Hind-Gullet. 



This commences at the outlet of the crop and continues for a 

 short distance (4 mm.) when it rapidly widens in the formation 

 of the gizzard. 



