NERVOUS SYSTEM 



79 



are given in table 46 and in chart 8 in which the observed values 

 are also entered. 



The theoretical curve in chart 8 has been computed by formula 

 (11). When a comparison is made between the calculated area 

 of the brain, (Suitsu, '20, p. 354) and that of the callosum, it 

 appears that in the Albino the area of the callosum is 3.29 per 

 cent that of the brain area while in man it is 4.44 per cent. 



Ql Q2 03 04 05 06 QT 08 09 10 11 12 13 i+ 15 16 IT 18 19 20 jp* 



Chart 7 Giving for each brain weight group, in millimeters, on brain weight 

 in grams, the values for the several diameters, W.B. and W.D., width; L.F. 

 and L.G., length; Ht., height. See equivalent designations, Figs. 3 and 3 a. 



= W.B. ooo = L.G. 



. . = w.D. o o = L.F. 



X----X X = Ht. 



Using the method of equivalent ages, the fibers in the callosum 

 of man should be well myelinated at the age of 20 months. 



Growth of the cerebral cortex in thickness (Sugita, '17 a). On 

 sections made in the three planes indicated in figures 4 and 5 

 the thickness of the cerebral cortex was determined at XIII 

 localities as marked on the sagittal section in figure 6, on the 

 frontal section in figure 7 and on the horizontal section in figure 8. 



