ON ANNELIDA. 125 



tremely fine ; sometimes they are so much so that it is impos- 

 sible to perceive them. In the middle of a space comprised be- 

 tween the internal roots of the dentiferous tubercles, is a round 

 orifice, extremely small, and conducting into the intestinal 

 canal. 



We have already said, that this last is not free and floating 

 in the visceral cavity ; in fact, its parietes are adherent by their 

 external surface, almost immediately to the muscular sheath, 

 by means of a stratum of cellular tissue, of a spongy aspect, of 

 a deep brown colour, and which may be very well considered 

 as hepatic. Be this as it may, the intestinal canal has its 

 parietes extremely slender; the mucous membrane is scarcely 

 less so : it forms longitudinal folds, very little marked ; they 

 are much more so in the whole length of the oesophagus, which 

 is very short, and all its parietes are distinct. Beyond this 

 is the stomach, which extends almost to the posterior sixth 

 of the total length of the body ; its most singular peculiarity 

 is, that in the leeches which are gorged with blood, we find it 

 divided by a considerable number of strangulations, and of 

 lateral pouches, most usually of a sigmoid form ; these pouches, 

 which some authors have regarded as stomachs, are vari- 

 able in number, according to the report of different authors. 

 The stomach of the leech, when completely empty, which is 

 the proper state in which it should be studied, and not in a 

 state of enormous distension, presents a great number of lon- 

 gitudinal folds, which converge or approximate at the entrance 

 of the sinuses. At the place where this stomach terminates, 

 it is again continued in a vast pouch on the right and left, 

 which extends as far as the extremity of the body, occupying 

 its entii-e breadth, and without its parietes being more sepa- 

 rated from the skin than the rest of the stomach. There 

 are also perceived strangulations formed by the transverse 

 muscular fibres, which have been named ccecums. The in- 

 testine, properly so called, is very short ; its communication 



