1017 
1.  Table  showing  the  total  numbers  of  axons  in  the  dorsal  and  ventral  roots  of  animals  of 
various  ages  in  the  same  species  and  of  different  species. 
Species. 
Age  in 
days  or 
length 
in  cms. 
Total  number  of 
axons  in  al)  the 
roots of thespinal 
nerves. 
Relation 
between  the 
numbers  in 
the  dorsal 
and  ventral 
roots. 
Average 
total. 
Percentage 
of  increase. 
Remarks. 
ventral 
roots. 
Dorsal 
roots. 
V.  r 
! D.  r. 
V.  r. 
D.  r. 
ifo  vulgaris. 
1.6 
3603 
4368 
1.2  : 1 1 
1.7 
3380 
4580 
1.36  : 1 
yf 
1.7 
2947 
4156 
1.4  : 1 
» yy 
1.7 
3242 
4312 
1.3  : 1 
j 
*1.8 
2937 
4025 
1.3  : 1 
3281 
4357 
i 
1.8 
3891 
4399 
1.1  : 1 
The  average 
1.8 
3661 
4367 
1.2  : 1 
1 
numbers  for 
the  most  dif- 
1) » 
1.9 
3130 
4650 
1.5  : 1 
ferent  sizes 
2 
2742 
1 
and  ages  of 
" " 
animals  are 
not  reliable, 
1.77  average  — * 
. 1.3  : 1 
78 
93.8 
because  the 
increase  in 
3 
4325 
6129 
1.4  : 1 
the  axons 
thatisshown 
1)  „ 
4.5 
5065 
6614 
1.35  : 1 
in  the  table 
5.8 
5209 
6647 
1.27  : 1 
does not pro- 
" " 
ceed  at  an 
» 1) 
6.8 
5284 
7824 
1.48:1 
1 
equal  pace 
1 
1 
during*  the 
II  II 
7.9 
5986 
1 
7783 
1.3  : 1 
5854 
8276  ) 
wholeperiod 
II 
9.4 
6293 
9222 
1.46  : 1 / 
1 
of  growth. 
8,03  ■«—  average  — ► 
1.41  : 1 
^us  rattus  5 
about  700 
53260 
94109 
1 
1.76  : 1 
53260 
94 109  ] 
2 
„ 350 
38906 
78466 
2:1 
116.9 
79.3 
..  „ 5 
10 
24554 
52469 
2.13  : 1 
24554 
52469 
» 5 
30 
29252 
51338 
1.75:1 
» ,,  5 
40 
30739 
57240 
1.86  : 1 [ 
226  ^ average  — »• 
■ 1.9  : 1 
Verslagen  der  Afdeeling  Natuurk.  Dl.  XXVll.  A".  1918/19. 
66 
