66 THE LAW OF BIRTHS AND DEATHS 



the fact that races living upon foods poor in proteids 

 are both deficient in nervous energy and very fertile. 



Without entering into the controversy between the 

 advocates of a meat diet and the vegetarians, it may be 

 said that meat appears to be more stimulating to the 

 nervous system. Of course, it must be borne in mind 

 that meat is a complete food, whereas vegetables are 

 not, so that the meat-eater is much less likely to be living 

 on a diet short of some essential constituent than the 

 vegetarian. But even allowing for that, a meat diet 

 seems to be more stimulating. Giving evidence before 

 the National Birthrate Commission, Dr. Starr Jordan 

 mentioned that in the course of an experiment carried 

 out at Stanford University of feeding rats, some upon 

 a vegetable and some upon a meat diet, it was found that 

 the meat-fed rats ran over 50 per cent, more ground 

 than the others. That suggests a more stimulating effect 

 from the meat. One authority says : "If proteid food, 

 therefore, be regarded as a nervous food, a diet rich in 

 it will make for intellectual capacity and bodily energy, 

 and it is not without reason that the more energetic 

 races of the world have been meat-eaters. 



" The difference, in fact, between an animal fed on 

 a highly nitrogenous diet, and one supplied with little 

 nitrogen, is the difference between a steam-engine at 

 half-pressure and one that is producing its full horse- 

 power. It is the difference between a tiger pacing its 

 cage and a cow lying upon the grass : both are healthy, 

 but the type or degree of health is very different in the 

 two cases." * 



Quantity is of importance as well as quality. An 

 under-fed man is very similar to an over-worked man. 

 Both are deficient in nervous energy. 



1 Food and the Principles of Dietetics, Robert Hutchinson, chap. x. 



