48 



long collatet-als duririfs ttiat part of its course lyin^ in the 

 substantia gelatinosa. 



The two kinds of neurones just described evidently con- 

 stitute the physical basis for the central reception of gener- 

 al cutaneous impressions. The first variety, with its short 

 axone, is so concerned entirely, it would seem; while the sec- 

 ond one described, having its axone proceeding to deeper re- 

 gions, is probably involved to an equal degree in both the 

 reception of impressions and in their distribution to deeper 

 levels. 



Still a third type of neurone remains to be described 

 (F'ig.-5,c.). From an oval cell-body, a few sparsely branching 

 dendrites arise which lead far out into the surrounding field. 

 The axone takes a course into the deeper nervous matter, giv- 

 ing off only a few collaterals. This form of neurone is found 

 outside the margins of the groups, and apparently is purely 

 associative in function. 



c. The Deever Heurones. — The deeper parts of the gener- 

 al cutaneous nucleus are occupied by fibres having courses in 

 several different directions, and by the bundles of the spiral 

 V tract. Neurones are scattered at intervals between the nerve- 

 fibres, with a somewhat more closely crowded area just dorsal 

 to the lobus vagi. Neuroglia is especially abundant in all 

 parts of the nucleus, providing a support for the intricate 

 ma?e of nervous structures. 



