CHAPTER V. 



INCREASE OF THE BRAIN IN WEIGHT AND VARIA- 

 TIONS OF THE CRANIUM IN CAPACITY. 



Table and chart of increase in brain-weight with age Weight at 

 birth Weight in the still-born Early growth Proportional 

 growth Spinal cord Changes in composition Cessation of 

 growth Venn's observations Length and breadth of head 

 Brain-weight in different races Cranial capacity Determina- 

 tion of exact weight. 



THE increase in the weight of the brain during the 

 earlier years of life is an important change, for which 

 the most complete observations are those furnished by 

 Vierordt in the accompanying table. 1 In this table the 

 two sexes are considered separately, and the growth of 

 the brain indicated by recording its average weight in 

 persons dying at the respective ages ; though in some 

 instances it will be noticed that the number of cases for a 

 given year is much smaller than is desirable for the best 

 results. The curves into which these figures have been 

 thrown for graphic representation show decided irregu- 

 larities, probably due to this same fact : nevertheless it 

 is also true that the general character and relations of 

 the two curves are not disturbed by these defects, and 

 that certain broad conclusions may be safely drawn 

 from them. 



1 Vierordt, Arch. f. Anat. und Physio I. , 1890. 

 103 



