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 Alloltiboplwra. Dissections from the left side of A, the 

 twelve anterior segments (X 5), and 15, three se^ini tits in the intestinal region 

 (x 10.) The arrows indicate the course of the circulation. (From Howry'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 ^nnsjlion ; g. n, ganiUionic swelling of 

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

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

 '. 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 ; cc, gullet ; ce. 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 



