GROWTH OF THE FETAL CENTRAL NERVOUS SYSTEM 469 
0 1 & E) 4 5 6 T 8 9  Omos. 
Fig. 28 A series of curves illustrating the percentage increment of the various 
volumetric determinations of the brain, brain parts, and spinalcord. Abscissa: 
total time in fetal months as determined by Mall’s convention. Ordinates: per- 
centage increments calculated from the formulae of respective absolute growth 
curves. (Data from tables 2, 4, 5, 8, 10, 12, 18, 24, 28, and 34.) I, percentage 
increment of spinal cord volume. II, percentage increment of pons and medulla 
volume. III, percentage increment of midbrain volume. IV, percentage in- 
crement of cerebellum volume. V, percentage increment of both hemisphere 
volume. VI, percentage increment of the encephalon volume. VII, percentage 
increment of the volume of the central nervous sytem. VIII, percentage in- 
crement of the encephalon weight (cases collected from the literature). 
