No. 491] 



NOTES AND LITERATURE 



723 



Although this method of subdividing the nervous organs and classi- 

 fying their parts has many points of advantage over the older topo- 

 graphical method, it possesses as elaborated by Johnston its weaknesses 

 and these are most clearly seen in the way in which certain organs of 

 special senses are dealt with. The eye and its nervous connections 

 are put in the somatic afferent division not because they are concerned 

 with touch or any of the derived senses, but because in certain of the 

 lower vertebrates the spinal nerve terminals are stimulated apparently 

 by light. Tlie olfactory apparatus is classed under the visceral sen- 

 sory division because it is concerned with the acquisition of food. 

 The weakness of this classification is api)arent from tlie fact that 

 the reasoning by which the author is led to assign the olfactory appara- 

 tus to the visceral sensory division, if applied to the optic a])paratus, 



The Sense of Touch in Mammals and Birds." TIk^ liilc ot this 



