32(5 READINGS IN BIOLOGICAL SCIENCE 



20 years following 1920, have caught up with and now exceed the birth 

 rate of foreign-born women, with an annual rate of 50.7 children per 1,000 

 women, as against 49.5 per 1,000.* 



Hooton reports the results of a study of Harvard University under- 

 graduates which showed an increase in body size for three generations.'' 

 The men in the third generation had increased in height nearly one and 

 one-half inches over their grandfathers and more than 10 pounds in weight. 

 Generally speaking, the grandsons' measurements exceeded those of their 

 grandfathers by 2 per cent. The shoulder breadth of the grandsons was 

 greater than that of the grandfathers, but the depth and expansion of their 

 chests were less. While the bony structure of the grandsons was longer 

 than that of their grandfathers, it was more fragile. Though admitting that 

 their impressions had not been scientifically verified, Hooton stated that 

 he and other physical anthropologists believe the grandsons are constitu- 

 tionally weaker than their more compact grandfathers. 



Carrel commented on the magnificent physiques of our college athletes, 

 but remarked that their longevity is no greater than that of their ancestors 

 and their resistance to fatigue and worry seems to be less. He said they 

 have more delicate nervous systems than their ancestors and break down 

 more easily. 



It is a matter of common knowledge that average men of primitive races 

 isolated from civilization are capable, as a matter of routine, of sustained 

 physical efforts that seem prodigious to us. The men of the Hunzas, a tribe 

 of northern India, frequently travel 60 miles on foot in one stage, transact 

 business, and make the return trip immediately. The Austrahan Aborigines, 

 the polar Eskimos, and the many other peoples among whom Price made 

 his comparisons of primitive and modern diets and their effects, all were 

 endowed with a physical and nervous stamina far surpassing that of our 

 most rugged and highly trained athletes. 



In weighing the evidence of increase in size, two additional considera- 

 tions should be kept in mind. One is that the more notable increases re- 

 ported have been among descendants of foreign-born whose ancestors 

 frequently were undernourished for generations. The other is that anthro- 

 pological opinion does not hold a mere increase in size alone as indication 

 of biological improvement; the rate of metabolism frequently fails to keep 

 pace with the increase in size, with the result that the larger organism may 

 be less efficient than the smaller organism as a converter of food into 

 energy. 



Regardless of differences of opinion as to its evolutionary significance, 

 leaders of the rnedical profession and alUed branches of scholarship regard 

 degenerative disease as civilization's major health problem. Even making 

 the most generous allowance for the advances in the art of diagnosis, which 



^ Time Magazine, December 25, 1944. 

 "^ Twilight of Man, pp. i-ji-ij^. 



