GROWTH OF THE FETAL CENTRAL NERVOUS SYSTEM 429 
The two linear measurements of the cerebral hemispheres (the 
fronto-occipital and the temporal diameters) also furnish some 
information concerning the growth of this part of the brain. The 
855 5 10 15 20 kD 2.8) 35 40 45 HOM MDI. 
Fig. 7 Field graph and curve (connecting each 5-cm. crown-heel interval) 
of the per cent which the volume of both cerebral hemispheres forms of the en- 
cephalon volume. Abscissa: total body length inem. Ordinate: hemisphere 
volume in per cent of the encephalon volume. Individual cases indicated by 
solid dots. (Data from table 40.) 
fronto-occipital diameter is a very constant measure, due perhaps 
to its close conformance to the skull and to the fact that it is not 
affected greatly by the torsion of the brain parts or of the brain 
axis during growth. Its reliability has justified its use to some 
extent as a basic measurement. 
