72 THE EARTHWORM. 



2. The pharynx, which follows the buccal cavity, has thick 



muscular walls connected with the body-wall by 

 strands of muscle which run obliquely backwards 

 perforating the anterior septa. The pharynx 

 extends backwards about as far as the sixth or 

 seventh annulus when the animal is in an average 

 condition of extension ; but it lies entirely in front 

 of the septum dividing the fifth segment from the 

 sixth (fig. 25), 



3. The oesophagus is a concertina-like tube extending from 



the pharynx to the thirteenth or fourteenth segment. 



a. The oesophageal pouches are a pair of short lateral 



diverticula of the oesophagus lying in segment x., 

 and opening into the oesophagus at the anterior 

 end of segment xi. At certain seasons they con- 

 tain concretions of more or less crystalline cal- 

 careous matter, chiefly calcium carbonate. 



To see these oesophageal pouches, press aside the large 

 white vesiculce seminales which hide them. 



b. The oesophageal glands are two pairs of lateral 



protuberances on the sides of the oesophagus in 

 segments xi. and xn. They are hollow, and their 

 cavities, which are subdivided by a large number 

 of horizontal lamellae, contain a milky calca- 

 reous fluid. They are local thickenings of the 

 glandular walls of the oesophagus, and their 

 numerous cavities open into the oesophageal 

 pouches. 



C. Both the glands and the pouches are highly vascular 

 and play an important part in relation to the 

 lime of the soil and possibly also in regard to 

 respiration. 



4. The crop is a large dilated portion of the alimentary 



canal in segments xm. to xvi., but when filled it 

 encroaches upon the segments in front, pushing the 

 septa before it (fig. 25). 



