422 HALBERT L. DUNN 
140 per cent for the 10-to-15-cm. interval. It descends rapidly 
to 75 per cent of the 25-to-30-cm. interval, and then more 
slowly to 40 per cent in the 50-to-55-cm. interval. 
The percentage increment of the entire brain volume when 
calculated against age in fetal months (fig. 28, curve VI) is about 
580 per cent in the fourth month, descending to 22 per cent in 
the tenth month. 
Ort 5) 0p ee ON SIO 05S SAO Bam. 
Fig. 3 Field graph and curve of the growth in weight and volume of the en- 
cephalon in fetal life (the curve of growth taken from brain weights reported in 
the literature). Abscissa: total body length in cm. Ordinate: entire brain 
weight and volume in grams (cc.). Individual cases are indicated by solid 
dots (for weight). J, curve of encephalon volume drawn to the formula: 
Y = (0.125X)316 + 1.5.——== (Data from tables 3 and 4.) JJ, curve of 
encephalon weight based upon data from the literature and drawn to the form- 
Was Yi (ONS A Ee = RO n oe) ie eeeee (Data from tables 5 and 6.) 
