MUSCLES OF THE EARTHWORM 



147 



on the ventral wall of the somite (Figs. 55 and 58). All of the 

 turns are richly supplied with blood vessels. 



If carmine powder is injected into the coelom, it is taken up 

 by the chlorogogue cells, which then break down, freeing the 

 carmine together with fragments of the chlorogogue cells, and 

 all are caught up by the current made by the nephrostome, and 

 carried through the nephridium to the outside. From this 

 experiment the conclusion has been drawn that some, at least, of 



FIG. 58. Xephridium of Lumbricus. /, Funnel or nephrostome; ds, dissepi- 

 ment; n.t., narrow tube, ciliated between a and b, d and e and at c; m.t., middle 

 tube ciliated between // and /; w.t.,- wide tube; w./>., muscular part; ex, external 

 opening. (From Sedgwick and Wilson, after Benham.) 



the waste matters of the tissues are brought in the circulation 

 to the chlorogogue cells, and are acted upon by the fluids of these 

 cells. The products of this activity are liberated into the coe- 

 lom by the fragmentation of the cells, and then are excreted from 

 the worm by the nephridia. 



Dorsal Pores. Excretion is also carried on to a limited extent 

 through dorsal pores situated in the annuli in the mid-dorsal 

 line. 



G. THE MUSCULAR SYSTEM. The main muscular and sup- 

 porting system of the earthworm is relatively simple, consisting 

 of two walls of muscle fibers which form a continuous sheath from 

 anterior to posterior ends of the worm. Being united with the skin 

 to form the body wall, it is known as dermal musculature. The 



