60 THE EARTHWOEM 



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. 23). 



3. The oesophagus is a straight tube extending from the 



pharynx to the thirteenth or fourteenth segment. 

 When the animal is not fully extended the oesophagus 

 appears dilated in each segment, and constricted 

 where it perforates the septa. 



a. The oesophageal pouches are a pair of short lateral' 



diverticula of the oesophagus' in segment x. At 

 certain seasons they contain concretions of more 

 or less crystalline calcareous matter, chiefly cal- 

 cium carbonate. 



To see these oesophageal pouches press aside the large white 

 'oesiculcB seminales which hide them. 



b. The oesophageal glands are two pairs of lateral pro- 



tuberances on the sides of the oesophagus in seg- 

 ments XI. and XII. They are hollow, and their 

 cavities, which are subdivided by a large number 

 of horizontal lamellae, contain a milky calcareous 

 fluid. They are local thickenings of the glan- 

 dular walls of the oesophagus, and their nume- 

 rous cavities open into the oesophageal pouches. 



4. The crop is a large dilatation of the alimentary canal in 



segments xiii. to xvi., but when filled it encroaches 

 upon the segments in front, pushing the septa before 

 it (fig. 28). 

 .5. The gizzard extends from the sixteenth segment back- 

 wards to about the twentieth. Its walls are very 

 thick and muscular, and it has a thick chitinous 

 lining. 



