9-2 



THE VITAL FUNCTIONS. 



O 



262 



these worms is observed to be transferred from tfie 

 one to the other of its numerous stomachs, back- 

 wards and forwards many times, before its diges- 

 tion is accomplished.* 



The stomach of the Leech is very peculiar in its 

 structure: its form, wlien dissected 

 off, and removed from the body, 

 is shown in Fig. 260. It is of 

 great capacity, occupying the 

 larger part of the interior of the 

 body ; and its cavity is expanded, 

 by folds of its internal membrane, 

 into several pouches (c,c,c). Mr. 

 260 i/S»«ffi9L Newport, who has examined its 



structure with great care, finds that 

 each of the ten portions into which 

 it is divided sends out, on the part 

 most remote from the oesophagus 

 (o), two lateral pouches, or caeca ; 

 which, as they are traced along 

 the canal, become both wider and 

 longer, so that the tenth pair of 

 caeca (a) extends to the hinder ex- 

 tremity of the animal ; the intes- 

 tine (i), which is very short, lying between them.f 

 It has long been known, that if, after the leech, 

 has fastened on the skin, a portion of the tail be 

 cut off, the animal will continue to suck blood for 



* The internal surface of the intestine and caecal appendages of 

 the Aphrodita, and other Annelida; and also of the entire ali- 

 mentary canal of the MoUusca is furnished with cilia. 



+ This figure was engraved from a drawing made, at my request, 

 by Mr. Newport, from a specimen which he dissected. Fig. 251 

 represents the mouth, within which are seen the three teeth ; and 

 Fig. 262, one of the teeth detached. 



