GENERAL REMARKS ON THE SENSES. 



517 



and in every instance we can distinguish between sensory im- 

 pulses generated in the end-organ, conveyed by a nerve inward, 

 and those in the cells of these central nervous systems, giving 

 rise to certain molecular changes 

 which enable the mind or the 

 ego to have a perception proper ; 

 which, when taken in connec- 

 tion with numerous past experi- 

 ences of this and other senses, 

 furnishes the material for a sen- 

 sory judgment. 



The chief events are, after 

 all, internal, and hence it is 



Fig. 372. 



Fig 373. 



Fig. 372.— Corpuscle of Vater (after Sappey). 



Fig. 378.— Eud-bulbs (corpuscles) of Krause (after Luddon). A, from conjunctiva of 

 man; B, from conjunctiva of calf. It may be noticed that in all tbese cases the 

 nerve loses its non-essential parts before entering the corpuscle, 



found that the higher in the scale the animal ranks, the more de- 

 veloped its nervous centers, especially its brain, and the more it 

 is able to capitalize its sensory impulses ; also the greater the de- 

 gree of possible improvement by experience, a difPerence well 

 seen in blind men whose ability to succeed in life without vision 

 is largely in proportion to their innate and acquired mental 

 powers. Inasmuch as all cells require rest, one would expect 



