154 PHYSIOLOGY. 



Effect of Cold on Appetite for Fats. In cold climates 

 a large amount of fat is consumed, while in the tropics 

 starch is the chief food. Our appetites call for more of the 

 fatty foods during the winter season. 



Proper Diet. While common experience has led people 

 to adopt a mixed diet, the proportions of the different food- 

 stuffs is not always what it should be. The proportions 

 of the foodstuffs (exclusive of water) may be roughly stated 

 as about I part of proteid, I part of fat, 3 parts of carbo- 

 hydrates. But this will vary somewhat with the amount 

 of work done, and other varying conditions. 



Vegetarians. The so-called " vegetarians " recognize 

 the need of proteid food, and most of them seek proteid in 

 eggs, milk, and cheese. But these are animal products, 

 and the name " vegetarian " is inconsistent. They are 

 merely " anti-meat eaters." If they do actually succeed 

 in getting enough proteids from the legumes and the 

 grains, the complete digestion of which is difficult, they 

 are, as Professor Martin says, to be congratulated on having 

 digestive powers that can stand such a strain. That we 

 are adapted for using flesh as part of our food is indicated 

 in at least two anatomical features: (i) we have canine 

 teeth, though not so fully developed as in the carnivora ; 

 (2) the intestine in carnivora is very short, that of the 

 herbivora very long, but in man intermediate. Neverthe- 

 less, it is undoubtedly true that many persons eat too much 

 meat. 



Tea. Tea owes its stimulating effects to a substance 

 called thein. This is a stimulant to the nervous system, 

 but if not too strong is not followed by a subsequent 

 depression. Tea that is too strong is likely to produce 

 nervousness and dyspepsia. Boiling the tea leaves also 



