58 JOURNAL OF COMPARATIVE NEUROLOGY. 
circles between the second and third primary circles were con- 
sidered magnified 68.15, 68.30, 68.45, 68.60, 68.75, 68.90, 
69.05 diameters respectively. The actual areas of the fascicles 
were then found by dividing the areas of the projections of the 
fascicles by the square of the magnification as determined 
TABLE Ila. 
Areas in sq. mm. of Cross-Sections of the Dorsal Nerve Roots of the 
Spinal Nerves of Man. 
Average 
length of Seg- KOLLIKER INGBERT STILLING 
No. of Spinal ments in mm. 
Segments according to 
DONALDSON Male Male Female 
and Davis # 
I a2 -43 203 238 
II 9.7 BES 2.33 2.18 
= III 12.4 2.81 2.14 Ieee 
= IV 14.3 1.95 2.01 1.39 
x M 12.4 3.87 2.82 2.27 
oO VI 13.8 6.04 4.65 4-41 
VII 12.9 7.06 4.72 3.76 
WANE E32 5-75 di 450s 
I 12.8 2.SI 1.79 als 
II 14.2 1.54 -97 ene 
III 78 1.00 98 0.96 
IV 20.9 1.00 .9O 73 
S V 21.9 1.08 .68 78 
a VI 23 6 1.73 .59 45 
ie VII 24.2 Ke 98 ays 
a Vill 25 17s yi! 85 
IX 23.5 1.63 .67 .87 
x 227.5 1.79 .86 82 
XI 21.4 1.84 gI .99 
XII 19.6 1.73 1-2 .88 
z I 18.3 1.90 tes Tee 
S II 12.9 DE37, 222 1.50 
g Ill 11.8 2.81 2253 2257 
is LING 10.6 3-99 2.93 3-49 
é 
\ 8.2 4-49 3.20 3-39 
I re 7-06 3-44 3.96 
= II 8.4 3-99 1.92 5.52 
5 III Wat I.U1 1.18 2EG8 
Ss IV 6.7 48 .40 1.24 
V 4.8 23 a0 0.47 
2) 
5 I ov 04 03 II 
