959 

 TABLE a. 



Author. 



Animal. 



Nerve. 



Number of Number of moduUated 



nerve cells, fibres in the dorsal root. 



F^'roin this table we see that the number of nerve-cells is man}' 

 times greater than the ninnber of ineduUated axons in the dorsal 

 root belonging to them. Hatai*) has investigated the relation between 

 the large and the small cells in the ganglion spinale and has found 

 that in the white rat the small ones are about 60 pei- cent of the 

 total number. In the case of C II in the cat, Warrington and 

 Griffith') have found that the small cells in the ganglion compose 

 about 70 per cent of the total number. Hatai has investigated the number 

 of cells, both large and small, in the spinal ganglion and the number 

 of medullated nerve fibres in the dorsal roots of C VI, Th IV and 

 LII in animals of different ages oï Mnsnorveyicus alhinus. A j-ésumé 

 of the values obtained by him is given in the following table h" . 

 (See table b following page). 



With regard to the views of different wi-iters on this subject as 

 to the number of nerve fibres in the dorsal root and the number 

 of cells in the spinal ganglion, all are agreed that the number of 

 cells is considerably greater than the number of medullated axons. 

 Those mentioned above have also investigated this relation only 

 according to the medullary sheath stains. Ranson, who has Cajal- 

 impregnated a spinal ganglion and the dorsal root appertaining to this 

 from a dog, has shown the existence of non-medu Hated fibres in the 

 dorsal root, which he supposes to issue from the small cells in the 



1) Gaule und Lewin : Ueber die Zahlen der Nervenfasern und Ganglienzellen 

 des Kaninchens. Gentralbl. f. Physiol. Heft. 15 u. 16. 1896. 



') Hatai S. Number and size of the spinal ganglion cells and dorsal root-fibres 

 in the white rat at different ages. J. Gomp. Neur. Vol. 12. 



') Hatai, S. Preliminary note on the presence of a new group of neurones in 

 the dorsal roots of the spinal nerves of the white rat. Biol. Bull. Vol. 3. 



*) Ranson, S. W. Retrograde degeneration in the spinal nerves. J. Comp. Neur. 

 and Psychol., Vol. 16. Quoted by Donaldson I.e. (1915). 



S) Warrington. VV. B. and Griffith, F. On the cells of the spinal ganglia and 

 of the relationship of their histological structure to the axonal distribution. Brain. 

 Vol. 28. Quoted by Ranson. 1912 I.e. 



