2l6 



PHYLUM ANNELIDA. 



detected in the gut, a diastatic ferment turning the starchy food into 

 sugars, and others peptic and tryptic not less important. The wall 

 of the stomach-intestine from without inwards, as may be traced in 

 sections, is made up of pigmented peritoneum, muscles, capillaries, 

 and an internal ciliated epithelium. In the other parts of the gut the 

 innermost lining is not ciliated, but covered with a cuticle. 



Vascular system. The fluid of the blood is coloured 

 red with haemoglobin, and contains small corpuscles. Along 



,A 



FlG. 112. Transverse section of earthworm. 



A., Cuticle; B., epidermis; C.M., circular muscles; L.M., longitudinal 

 muscles; Z>., a seta ; C., coelom ; K.C., yellow cells; F., typhlosole ; 

 V.V., supra-neural blood vessel; S. V*> sub-neural vessel; D.I/., dorsal 

 vessel ; /'., peritoneum; E. t cavity of gut ; ., endodermic lining of gut ; 

 N. t part of a nephridium ; R., opening of a nephridium ; /., the nerve- 

 cord ; /., a nerve given off; K., giant fibres in the nerve-cord. 



the median dorsal line of the gut a prominent blood vessel 

 extends, another (supra-neural) runs along the upper surface 

 of the nerve-cord, another (infra-neural) along the under 

 surface, while two small latero-neurals pass along each side 

 of this same cord. All these longitudinal vessels, of which 

 the first three are most important, are parallel with one 

 another ; the first three meet in an anterior network on the 



