68 



wall into the cavity, or even free in the cavity of the 

 intestine itself. Many of these are possibly migrating 

 cells taking up food matters and again passing hack 

 through the intestine into the blood stream, but there can 

 be little doubt that many are the products of secretion 

 of cells in the intestinal wall itself or in the tissue lying 

 round that wall. Masses of a dense tissue staining with 

 haematoxylin in the same manner as the mucus-secreting 

 cells in the foot and mantle are to be found along the 

 whole length of the intestine. 



The faecal matter is expelled from the intestine in the 

 form of coherent strings, frequently of great length, in 

 which the particles are certainly bound together by some 

 viscous material. On Barrois' view this faecal matter 

 ought to contain a substance chemically identical with the 

 substance of the style, otherwise, transformation of the 

 latter goes on in the intestine, and the substance of the 

 style must function otherwise than as a simple lubricant. 

 On the whole it would seem as if the presence of the style 

 were associated with the ingestion of a large quantity of 

 foreign matter, such as mud and sand, and the separation, 

 to some extent, of the nutrient material therefrom. The 

 substance of the style need not be regarded as physiolo- 

 gically a store of reserve material, but as a first separation 

 out of some constituents of the food which are continuously 

 lodged in a portion of the stomach by the action of the 

 cihated wall of the latter, and as continuously dissolved 

 away. 



A narrow slit on the anterior surface of the straight 

 portion of the gut leads into the next division — the spiral 

 portion of the intestine. This lies nearly in the axis of 

 the proximal limb of the viscero-pedal mass, and anterior 

 to the latter. It is twisted into a close spiral of five or six 

 turns {Al.c.4, hgs. 3 and 11) the planes of which are 



