A428 HALBERT L. DUNN 
The per cent which the volume of both hemispheres forms of 
the entire brain volume (fig. 7) reflects the relative growth of the 
other brain parts. The cerebral hemispheres form only from 
7A 
JO 
0 eet F - — - : 
O 5 10 15 40) 05 SO oD AO AD5 50 55cm. 
Fig. 6 Field graph and curve of the growth in weight and volume of both 
cerebral hemispheres in fetal life. Abscissa: total body length in em. Ordi- 
nate: hemispheres weight and volume in grams (ce.). Individual cases indicated 
by solid dots (for weight) and by circles (for volume). Curve drawn to the 
formula: Y = (0.12X)*19. (Data from tables 11 and 12.) 
88 to 90 per cent of the entire brain volume in the third fetal 
month. ‘This proportion increases rapidly to between 94 and 95 
per cent during the sixth fetal month, but after this time it de- 
scends to about 91.5 per cent at birth. This decline is due 
mainly to the tremendous relative growth of the cerebellum. 
