J026 
TABLE  a. 
Author. 
Animal. 
Nerve. 
1 
Number  of 
nerve  cells. 
Number  of  modullated 
fibres  in  the  dorsal  root. 
Gaule  and  Lewin  ') 
Rabbit 
Cocc.  I 
20361 
3173 
Hatai  H (02) 
White  rat 
C.  VI 
12200 
4227 
Hatai  2)  (02) 
L.  II 
9442 
1644 
Ranson  4)  (08) 
C.  II 
7721 
2472 
From  tliis  table  we  see  tliat  tlie  iinmher  of  nerve-cells  is  many 
tiiiies  grealer  tlian  tlie  oniuber  of  iiiediillated  axons  in  the  dorsal 
root  belongitig  to  tliem.  Hatai'^)  lias  investigated  the  i’elation  between 
the  large  and  tlie  sniall  cells  in  the  ganglion  spinale  and  lias  found 
that  in  the  white  rat  the  sniall  ones  are  abont  60  per  cent  of  the 
total  nmnber.  In  the  case  of  C II  in  the  cat,  Warrington  and 
Griffith®)  have  fonnd  that  the  small  cells  in  the  ganglion  compose 
abont  70  per  cent  of  the  total  nmnber.  Hatai  lias  investigated  thenumber 
of  cells,  both  large  and  sniall,  in  the  spiiial  ganglion  and  the  number 
of  rnedullated  nerve  fibres  in  the  dorsal  roots  of  C VI,  Th  IV  and 
L II  in  animals  of  ditferent  ages  oï  Mus  norvegicus  albimis.  A résumé 
of  the  valiies  obtained  bj  hiin  is  given  in  the  following  table  6'. 
(See  table  b following  page). 
With  regard  to  the  views  of  ditferent  writers  on  tliis  subject  as 
to  the  number  of  nerve  fd)res  in  the  dorsal  root  and  the  number 
of  cells  in  the  spinal  ganglion,  all  are  agreed  that  the  number  of 
cells  is  considerablj  grealer  than  the  number  of  rnedullated  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-niedullated  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,  181)6. 
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.  Buil.  Vol.  3. 
^')  Ranson,  S.  W.  Retrograde  degeneralion  in  the  spinal  nerves.  J.  Comp.  Neur. 
and  Psychol.,  Vol.  16.  Quoted  by  Donaldson  1.  c.  (1915). 
Warrington,  VV.  B.  and  Griffith,  F.  On  the  cells  of  the  spinal  ganglia  and 
of  the  relalionship  of  their  histological  structure  to  the  axonal  distribution,  Brain. 
Vol.  28.  Quoted  by  Ranson.  1912,  1.  c. 
