CIRCULATION IN THE ANNELIDA, 



255 



lar appendages are globular or oval dilatations 

 of some of the large vascular trunks, which bend 

 round the sides of the anterior part of the body, 

 and establish a free communication between the 

 dorsal and the abdominal vessels. They are 

 described by Dug^s as consisting, in the Lum- 

 hricus gigas, of seven vessels on each side ; form- 

 ing a series of rounded dilatations, about twelve 

 in number, resembling a string of beads.* 



In the Lwnhricus tei^restris, or common earth- 

 worm, there are only five pair of these vessels : 

 they have been described and figured by Sir 

 E. Home y\ but the most full and accurate 

 account of their structure has been given by 

 Morren, in his splendid work on the anatomy of 

 that animaLJ Fig. 349, which is reduced from 



349 



* They are termed by Dug^s, Vaisseaux moniliformes, ou 

 dorso-abdominaux. — Annales des Sciences Naturelles, xv, 299. 



t Philos. Transact, for 1817, p. 3 : and PI. iii. Fig. 4. 



X " De Lumbrici terrestris Historia naturalis, necnon Ana- 

 tomia Tractatus." Qto. Bruxelles, 1829. 



