338 



THE EARTHWORM 



CHAP. 



so that the blood passes forwards in the dorsal, back- 

 wards in the ventral vessel. The series of vessels of 



FIG. 83. Blood-vessels of Alloldbophora. Dissections from the left side of A, the 

 twelve anterior segments (x 5), and B, three segments in the intestinal region 

 (X 10.) The arrows indicate the course of the circulation. (From Howes's 

 Atlas.) 



be, buccal sac ; c. I, nerve-cord ; cm, commissural vessels connecting the dorsal 

 and subneural vessels ; cm', neural commissural vessels ; e. m, mesentery, and 

 ex, vessel of nephridium ; g. c, cerebral ganglion ; g. n, ganglionic swelling of 

 nerve-cord ; h, commissural vessels (" hearts ") connecting the dorsal and sub- 

 intestinal vessels anteriorly ; i, intestine ; i. I, lateral intestinal vessels ; 

 i. s, dorsal (supra-intestinal) vessel ; m. s, septum ; n. a, ventral perforation of 

 septum; n. I, lateral neural vessel ; n. s,_ sub-intestinal vessel ; n. s', subneural 

 vessel ; ce, gullet ; <x. g, cesophageal pouch ; ce. I, lateral cesophageal vessel ; 

 ph, pharynx ; sg. nephridium. 



the enteric canal are connected with the dorsal and sub- 

 intestinal trunks, and those of the excretory organs, to 

 be described presently, with the sub-intestinal trunk 



