2 76 TEE POPULAR SCIENCE MONTHLY 



cause. If liquor drinking is correlated with greater physical vigor in 

 men, an elimination of drinkers is also an elimination of vigor, and 

 would result in race deterioration. Social causes are simpler and deeper 

 seated than are social effects. A study of the types of men and of the 

 relation between the various groups of visible traits must therefore 

 precede attempts to modify races by the elimination of single traits. 



Prominent differences in men arise from the contrasting effects of 

 upland and lowland climates. An upland race, if in a dry region, has a 

 purer and more bracing atmosphere, and hence does not need so much 

 lung power. It must develop greater vigor and endurance, partly 

 because of the cold and partly because of the game it chases and 

 the cattle it herds. Its food is drier, harder and more condensed; 

 hence a better develojDment of the jaw and its muscles results; 

 along with this come smaller stomachs, better digestion and fresher 

 blood. A tall, narrow-chested man comes into being, who is in marked 

 contrast with the short broad man of the lowland regions. These 

 typical differences are accompanied by minor traits, not always found 

 in all of a given race, but often enough to indicate that they have the 

 same general causes. Long heads and round heads represent dynamic 

 changes, even if we can not trace them back to given climatic origins. 

 Some races and persons have a marked development of the lower 

 face with prominent jaws and strong facial muscles. These people 

 like hard foods, enjoy chewing their food, and, if possible, keep some- 

 thing in their mouth, gum or tobacco or the like, to exercise their jaws. 

 Baseball players are noted examples of this habit; it indicates a sur- 

 plus of energy and strong muscular development. It is equally plain 

 that those with a weak lower jaw and muscles take readily to soft sweet 

 foods, that they suck or gulp down rather than chew. This means a 

 better muscular development of the throat. A snake, for example, 

 sucks down its food, while a tiger chews his. In men the sweets and 

 the meats are causes that bring out this difference between the chewers 

 and suckers. Another like contrast is between the mouth breathers and 

 the nose breathers. We speak of breathing as a habit, and yet different 

 habits would not tend to be formed if muscular differences did not exist. 

 Each activity is the outlet of energy, which tends to express itself 

 through bodily mechanisms. The strong grows at the expense of the 

 weak; each difference in bodily powers tends to develop a type. 



These contrasted traits are valuable, not so much for the definite- 

 ness of their manifestation as for the general conclusion their study 

 warrants. The two t3^pes of men differ somewhat in their dynamic 

 characters, but more in the environmental modifications which climate, 

 food and occupation have created. The upland types are tall, bony, 

 narrow-chested with well developed lower faces. They breathe through 

 the nose and eat hard foods. The lowland types are short, thick set, 

 live on soft foods, and use large quantities of coarse or liquid foods. 



