LUMBRICUS TERRESTRIS 



163 



their granules, which are taken up by amcebocytes. It is said that 

 these may go to the exterior, but as the granules contain only 

 four per cent, of nitrogen they cannot be an important excretory 







Wkm^-:. 



^-ei 





gi-.c. 



Fig. 112. — Histology of the earthworm. 



A , The end of the first hank of the nephridium ; A' , part of a section of the same ; B, part of a transvers 

 section of the body. 



br.t., Brown, ciliated tube ; b.v., blood vessel ; c.c, chloragogenous cells ; c.m.b., circular muscle of body 

 wall ; c.m.g., circular muscle of gut ; cu., cuticle; ep., epidermis ; end., endoderm ; g.f., giant fibres; 

 gl.c, gland cell in the epidermis ; l.m.b.^ longitudinal muscle of body-wall ; l.m.g., longitudinal muscle of 

 gut ; l.n.v., lateral neural vessel ; n., nerves ; n.c, nerve cord ; n.c.t., glandular, non-ciliated tube ; 

 n.f., nerve fibres; n.t., narrow tube, ciliated in parts; p.e.b., peritoneal epithelium of body-wall; 

 s.i.v., subintestinal blood-vessel ; s.n.v., subneural blood vessel ; ves.tiss., connective tissue with 

 vesicular cells and blood vessels. 



product. There are also amceboid yellow cells which take up ex- 

 creta in the blood, pass into the gut, and are voided with the faeces. 

 Food swallowed in the course of burrowing is passed along the 

 oesophagus, stored in the crop, ground up in the gizzard with 

 the aid of small stones which have been swallowed, and in the 

 intestine first digested by juices secreted from the epithelium, 

 and then absorbed, for which processes the surface is increased 



