960 



spinal ganglion. R. writes: "It is to these non-nieduUated fibres, 

 the axons of the small spinal ganglion cells, that we are to look 



TABLE b. 



Weight of Total num- Large 



Small 



the body ber of cells, cells. cells. 



Relation 



between 

 large and 

 small cells. ^^^"^ 



Medul- 

 lated 



Relation be- ' Relation be- 

 tween the tween medul- 

 medullated lated axons 

 axons and and the large 

 the cells. cells. 



C. VI 



ThIV 



L II 



10996 



9793 



11772 



12200 



7142 

 7068 

 7611 

 7406 



8315 

 8200 

 9514 

 9442 



1:3,4 

 1 :3 

 1:2,3 

 1:1,4 



1 :3,5 

 1 :2,9 

 1 : 2,2 

 1 : 1,5 



1 :3,4 



! :3 



1 : 2,2 

 1 : 1,5 



1998 

 2569 

 3683 

 4227 



607 



863 



1420 



1522 



723 



911 



1317 



1644 



1 :5,5 

 1 :4 

 1 :3,2 

 1 -.2,7 



1 :1,1 

 1 :8,2 

 1 :5,3 

 1 :4,3 



1: 11,5 

 1:9 



1:7,1 



1 :5,7 



1:1,2 

 1 : 0,92 

 1 : 0,97 

 1:1,1 



1 :2,5 

 1 :2,1 

 1: 1,6 

 1:1,2 



1:2,6 

 1 : 2,6 

 1:2,2 

 1:2,2 



for the explanation of the discrepancy between the nnnibei' of spinal 

 ganglion cells and niednlated afferent fibres. If a connt were made 

 the number would probably closely approximate to that of the spinal 

 ganglio'n cells." Thus Ranson thinks that in this way he has solved 

 the problem quoted from Heidenhain above. If, however, we examine 

 the figure 15 that R. includes in his work, we see that all the 

 black spots in this drawing cannot be axons, but that, if all points 

 exist in the preparation, most of them are probably precipitates of 

 silver. On the other hand a large number of these black dots, which 

 one can with good reason assume to be axons, show traces of a 

 medullary sheath. It is, however, difficult to decide such a matter 

 when one has not seen the preparation in question, but only what 

 is perhaps a skeleton drawing. My own investigations on this point 

 show, howe\er, that R. has gone too far when he writes "If a 

 count of the afferent fibres were made, the number would j)robably 

 closely approximate to that of the spinal ganglion cells." 



It is true that in counting the nerve fibres on the silver impreg 



