Alimentary System of Gryllota^xc australis. 121 



Upon the projections of the connective tissue are lone; cylindrical 

 epithelial cells with filamentous free border ; they taper towards 

 the attached end, and overarch the cell nests, leaving only a small 

 opening, dilficult to determine, which serves as a passage for the 

 cells of the nests, or their secretions into the cavity of the organ. 

 The cell-nests are composed of young cells at the base, crowded 

 together, which stain deeply ; they gradually become matured 

 towards the opening between the filamentous cells. I have con- 

 sidered the probability of these cell-nests being germinative 

 centres containing young cells of the epithelium which over- 

 arches them, but their dissimilar appearance as they reach 

 maturity, their greater number than the cylindrical cells, and 

 also their position in relation to them, has convinced me of the 

 improbability of such being the case. 



The Terminal Canal. 

 This is joined to the posterior extremity of the cseca, and after 

 describing several round turns in the body-cavity, ends at the 

 anus. It is necessary on account of structural difierences to 

 divide it into fore-, mid-, hind-, terminal canal, and rectum. Except 

 Cuenot, other writers have considered the mesodermal middle 

 intestine to extend as far back as a little anterior to the entrance 

 of the duct of the Malpighian vessels, and although this "is so, I 

 believe, in other of the Orthoptera, in Gryllotalpa there is no 

 reason for so doing, for there is no marked diflferentiation of the 

 cell-wall at this part. The musculature, however, changes 

 sharply which gives an altered appearance from the outside. 

 Further, the outer and inner muscle layei^s are both striated, 

 which is not in accord with Professor Packard's description of 

 the histology of the mid-intestine,^ and there extends a chitinous 

 intima throughout the whole of the passage.^ The muscles 

 surrounding the wall are reversed in order compared with the 

 anterior canal, so that the longitudinal fibres are outside the 

 annular muscles. 



The Fore- Terminal Canal. 



This is -i mm. long, and is surrounded by a thick layer of 

 annular muscles, with the exception of a small anterior portion. 



1 Zee. cil., p. 316. 2 Loc. cit.. p. 302. 



