GROWTH OF THE FETAL CENTRAL NERVOUS SYSTEM 461 
The first type, cerebral growth, is characterized by a constant 
growth in linear measurements from the second fetal month until 
birth, and shows a steady and relatively slow increase in volume 
O 5 10 15 LO £5 30 35), = 40 A5 50 55« 
Fig. 23 Field graph and curve of the growth of the spinal cord in fetal life 
as shown by the spinal cord length. Abscissa: total body length in em. Ordi- 
nate: spinal cord length incm. Individual cases indicated by solid dots. Curve 
drawn to the formula: Y = (10.0X).467 — 4.0. (Data from tables 36 and 37.) 
before the sixth fetal month and a constant but more rapid in- 
crease from that time until birth. Brain stem and cord growth, on 
the other hand, advances much faster previous to the seventh 
fetal month than it does in the last four months of fetal life. 
Cerebellum growth, on the contrary, proceeds slowly until the 
