480 FRANK E. BEDDAED. 



The part of the alimentary tract lying behind the typhlosole 

 is thus sharply marked off, and the distinction between it and 

 the terminal section is possibly an important one ; I should 

 be inclined to regard the "rectum" as being proctodseum. 

 The diameter of the rectum, as shown in the figure, gradually 

 narrows to the anus; its walls are marked by longitudinally 

 running furrows. 



In transverse sections the gut is seen to be lined by an 

 epithelium of tall columnar cells, broader towards their ex- 

 tremities and narrower at their attachment. The folds 

 observable (fig. 5) in such sections are, of course, due to the 

 longitudinally running furrows. Outside the epithelium 

 is a circular coat of muscular fibres, and outside this again 

 longitudinal fibres ; these latter do not form at all a thick 

 layer, and they are partly interspersed among the meshes of 

 a peculiar form of connective tissue which extends beyond 

 them, and forms the outermost wall of the intestine. This 

 connective-tissue layer is also found beneath the epithelium ; 

 in parts it consists of a meshwork of fine fibres with nuclei 

 present, chiefly at the nodal points ; in other parts the mesh- 

 work becomes very wide, and the tissue presents the appearance 

 of a fenestrated membrane ; the fenestrse are, relatively speak- 

 ing, small, and the tissue lying between them is somewhat 

 gelatinous in appearance, with fine fibrils passing through it 

 (fig. 3) ; nuclei are present, which are frequently attached 

 closely to the fenestrse, bulging out into these latter as depicted 

 in fig. 3. 



At the extreme end of the body these layers are not so con- 

 spicuous, owing to the crowding together of the last two or 

 three of the intersegmental septa, and the continuity of these 

 with the intestine. 



The coelomic space, on the ventral side of the body at any 

 rate, is almost filled with the nephridia, which form two 

 principal masses, one on each side of the nerve-cord. In a 

 single section several funnels can be seen connected with the 

 nephridia, and their ducts can be observed to perforate the 

 body-walls, and to open on to the exterior by many pores. 



