464 HALBERT L. DUNN 
TABLE 40 
Ratios of the volumes of the various parts of the central nervous system to the entire 
brain volume 
RATIO OF: 
CROWN-HEEL 
ane ae bal BEE rr os eet pee Midbrain | Cerebellum hei hee 
cm. ih ae ian | aK Ginnie bs.) 
5 to 10 4.70 
10 to 15 3.30 aia) 2.90 3.0 87.7 
15 to 20 2.40 3.6 2.40 3.0 90.9 
20 to 25 1.70 Ded 1.60 3), 1h 93.1 
25 to 30 1.50 ee, 1.40 3.0 94.0 
30 to 35 1.20 1.9 0.96 De teh 94.2 
35 to 40 0.81 ire 0.90 3.8 94.1 
40 to 45 0.90 1.6 0.87 4.4 93 .2 
45 to 50 0.84 il 4) 0.70 One, 92.0 
50 to 55 0.70 1.4 0.67 yas) 91.8 
TABLe 41 
Comparison or THC WeiGnTs AND VoLUMES 
or THE Spina Corp, THE Exmrc Brain AND THe Various Parts or THE Brain 
IN THE FetaL Periop 
Averact WeicHt (Gm) anpVotume (cc)in Each Ser Intervat (CH) 
Spinal Cord 
128 cases) 
Pons and Medulla 
109 cases 
Mid brain 
(109 cases) 
Cerebellum 
(115 cases) 
Righ! Cerebral Homspher 
(115 cases) 
| 
Left Cerebral Hemisphere 
(114 cases) 
Dolire Brain 
(I44 cases) 
Central Nervous Syslem’ 
6 cases, 
