77. C. 



The Nervous System of Worms 69 



nervous matter extends along the length of 

 the body; at each somite the cord swells 

 into a ganglion from which nerves pass 

 t o neighbouring 

 structures. These ;; 



nerves contain in- 

 coming (afferent) 

 fibres or paths, by 

 which impressions 

 made on the surface 

 of the animal's body 

 are conducted to the 

 central ganglion, 

 and outgoing fibres 

 (efferent) commenc- 

 ing in the ganglion 

 and terminating in 

 effective structures 

 such as muscles or 

 glands. The class 



FIG. io. Diagram of nervous system 



of beingS tO Which of Annelida. 5, brain ; c.n., cephalic 



nerves to supply sense organs of 



5 belong, anterior end of the worm ; n.c., nerve 



1 cord passing from the brain to s.e.g., 



US not Only the sub-cesophagoal ganglion ; s.g., 



1 r U segmental ganglia giving off nerves 



an example OI the to the corresponding segments of the 



, . , , bodv. (Human Speech, Fig. 30, 



way in which their p . I2 6.) 



