PHYLUM ANNULATA 



469 



its 

 in 



Radiating muscles pass 

 from its walls to the 

 integument, and by 

 their contraction dilate 

 cavity and suck 

 blood from the 

 wounds made by the 

 jaws. Around the 

 pharynx are numer- 

 ous unicellular salivary 

 glands, which open 

 close to the mouth : 

 their secretion has the 

 effect of preventing 

 the coagulation of the 

 blood taken as food. 



The pharynx com- 

 municates by a very 

 small aperture with 

 the second and largest 

 division of the enteric 

 canal, the huge crop 

 (cr.), a thin-walled 

 tube extending from 

 the eighth to the 

 eighteenth segment, 

 and produced into 

 eleven pairs of lateral 

 pouches (cr. 1, cr. 11), 

 the first ten of which 

 are directed outwards 

 and correspond each 

 to a segment, while 

 the eleventh (cr. 11) 

 passes directly back- 

 wards as far as the 

 twenty - fourth seg- 

 ment. The crop is 

 capable of great dila- 

 tation, and its form 

 varies greatly accord- 

 ing to whether it is 

 empty or gorged with 

 blood. Posteriorly the 

 crop communicates by 

 a minute aperture with 

 the stomach (st.), a 



pfi 



cr.f. 



erf. 



t> 



cus_ 



va, 



cr.ff __, 



cr.ff 



