20 



build: definition and ontogeny. 



ination of such developmental curves as are shown in figure 6 strongly 

 indicates that when the parents are of slender build, and the children 

 are of slender build at the age of 25 years younger than the parents, 



the increase in weight of the children will not usually follow the 

 actuarial tables. The actuarial tables, indeed, represent only the 

 average increase, and this average is made of a population that does 

 not increase its weight at all when it grows older (fig. 6) and a popu- 



