506 



NAOKI SUGITA 



If, in table 4, the brain weight ratio be compared with the 

 ratio oi W. B x L. G X Ht. for any brain weight group, it ap- 

 pears that the values are nearly equal in the groups II-XII, though 

 some fluctuations under 0.2 may be seen. But in groups beyond 

 XII, the values in the two series deviate from one another; those 

 for the brain weight ratios being consistently larger. This shows 



TABLE 4 

 Giving Jrom birth to matimiy the ratios of the cube root of the brain weight, ratios 

 of W. B, of L. G and of Ht., and also the ratios of the products of these three 

 values 



roughly that in the brains weighing 0.25 to 1.20 grams the volume 

 and weight keep a fixed relation, but that in the brains weighing 

 more than 1.2 grams the total weight increases more rapidly 

 than the cerebral volume, as measured by the diameters which 

 were chosen. This relation probably depends on several causes. 

 1. As already noted, at the beginning of the present paper, the 

 cerebellum develops more rapidly than the other parts of the 



