NON-MEDULLATED NERVE FIBERS 77 



seen that their axons have been described by Dogiel and Cajal. 

 Furthermore v. Lenhossek ('95) says: ''There are no apolar cells 

 in the spinal ganglion;" and after a careful search for them Hodge 

 ('89) came to the same conclusion. 



V. Lenhossek ('95) has stated well what seems to be a correct 

 view of these cells: ''the smaller cells, even indeed the smallest 

 cells, are not to be regarded as functionless rudimentary struc- 

 tures, but as elements which just as truly as the large cells are 

 functional parts of the nervous mechanism: we find them associ- 

 ated just like the large cells with a process which divides in the 

 typical way," (into a central and a peripheral fiber). To this 

 must be added Hatai's observation that during the growing 

 period they are capable of transformation into large cells. 



Jj.. Numerical relations between the large and small cells 



Hatai ('02) enumerated separately the large and small cells of 

 the spinal ganglion of the white rat and showed that in the adult 

 animal the ratio between the large and small cells was, in the 

 fourth cervical ganglion as 1 is to 1.4, in the fourth thoracic as 

 1 is to 1.5 and in the second lumbar as 1 is to 1.5. In these 

 three ganglia of the adult white rat the small cells constitute 

 approximately 60 per cent of the total number. Warrington 

 and Griffith ('04), who worked with the second cervical nerve of 

 the cat, state that the small 'obscure' cells represent 68.1 per 

 cent and the small 'clear' cells 1.9 per cent or a total of 70 per 

 cent. In both investigations the structure as well as the size 

 was taken into consideration in determining which were large 

 and which were small. From these observations we may safely 

 say that in the cat and rat nerves studied about two-thirds of 

 the spinal ganglion cells may be classified as small. 



5. Numerical relations between the spinal ganglion cells and 



afferent fibers 



It has been shown by Hodge ('89), Biihler ('98), Hatai ('02), 

 Hardesty ('05), and Ranson ('08) that the spinal ganghon cells 

 are much more numerous than the medullated afferent fibers of 

 the associated dorsal root. Since the "distal excess" is small the 



