ANNULATA. 231 



along the alimentary canal between the nervous chord and the mucous 

 glands, and also upon the dorsal aspect of the anterior part of the 

 cavity. It is composed of a congeries of elongated, convoluted, and 

 irregularly constricted follicles, which are united in groups by the 

 confluence of their ducts into a single slender excretory tube. These 

 tubes unite with those of other groups of the follicles, and pour a 

 secretion, analogous to bile, into the posterior divisions of the stomach 

 and into the intestine. The confluence of the hepatic ducts is very 

 remarkable and conspicuous when they lie upon the testes.* 



The walls of the sacculated alimentary canal are connected with 

 the integument by a vascular tissue, like the corpus spongiosum, 

 mixed with many pigment cells. The chylaqueous fluid transuded 

 into this tissue is there taken up into the largely developed vascular 

 system. 



Terricola. — The mouth is furnished in the earth-worm with a 

 short proboscis, but is without teeth : a long lobulated salivary glan- 

 dular mass surrounds the pharynx. The decaying parts of animals 

 and vegetables are swallowed with the soil, and conveyed by a short 

 and wide oesophagus to a muscular compartment of the digestive 

 canal, analogous to a gizzard. The oesophagus is sometimes dilated, 

 like a crop, above this part. The long and wide intestine is con- 

 tinued straight to the terminal vent, and is constricted in its course 

 by the transverse septa of the common cavity of the body ; but the 

 sacculi are not produced into creca.^f Morren % describes a long and 

 slender blind tube, which he calls the " typhlosole," as being attached 

 to one side of the inner surface of the gut, in which tube he supposes 

 the chyle to be strained off" from the coarse contents of the wider sur- 

 rounding canal. A muscular compartment of the alimentary canal 

 maybe distinguished in Nais proboscidea, but not in Lumbriculus or 

 EnchytrcBus. The latter worm has four pairs of clear vesicles, which 

 pour their secretion into the gullet. 



Errantia. — In this order the pharynx is developed into a loose 

 and muscular cylinder, forming a kind of proboscis, provided with 

 special muscles for its protrusion and retraction, eversion and inver- 

 sion. It is short in Nereis, Eunice, and Peripatus ; longer in Gly- 

 cera, Phyllodoce^ and Polyno'e. In Arenicola, Chcetopferus, Aricia, 

 Phyllodoce, and Amphi7iome, the proboscis is unarmed : its everted 

 extremity is encircled by small papilla?. In Nereis, Lycastis, and 

 Peripatus, it is provided with a pair of strong, curved, horny jaws ; 

 and in other Errantia they are present in greater number : in Eunice, 



♦ CLXXXV. Bd. ii. p. 260. f Prep. No. 595. B. % CCXII. 



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