162 



SENSORIAL FUNCTIONS. 



Nervous Ganglia. The nerves, as they pass along 

 the different members often form ganglia, or knots, 

 which are small oval masses of nervous substance, con- 

 sisting of the ordinary filaments interlacing each other. 

 A ganglion is represented at g, Fig. 97, through which 



Fig. 97. 



the nerve n passes, consisting at its origin of a number 

 of separate filaments/*, and again, sub-dividing into many 

 branches b. 



A plexus, or net work of nerves, is shown by Fig. 98. 

 This is formed of four trunks, seen distinct at t, t, but 

 which variously interlace each other, at the same time 

 dividing into branches, before they proceed to their 

 respective destinations. 



The ganglia appear to be a kind of secondary senso- 

 ria, or rather perhaps reservoirs of the nervous power, 

 and in which nervous filaments from the neighboring 

 parts concentrate, or from which these filaments pro- 

 ceed. They are perhaps points where nerves convey- 

 ing different kinds of intelligence to the brain meet, and 

 by mingling their influence convey compound sensations 

 to the mind. 



But the subject of sensation and perception, as con- 

 nected with the powers of reasoning and reflection, do 

 not come within the scope of this volume, and we shall 



What are ganglia"? 

 ies of ganglia 1 



What is a plexus of nerves 7 What are the 



