MAN AS A HOMOIOTHERMIC ANIMAL 97 



Homoiotherms as a whole have become more or less in- 

 dependent of environment by attaining the ability to 

 maintain a constant and comparatively high body tem- 

 perature. Man, more than any other animal, is able to 

 live to his full capacity at all times. For this privilege 

 the constancy of the environment of his cells, tissues, 

 organs, and body is largely responsible. 



It is ^* human nature'' to long for stability. A man 

 believes that if he could cease to worry about making a 

 living and surviving, living better than his fellows (or 

 being a success), his state after his present life, and 

 other vexatious matters, he would be perfectly happy 

 and contented. But would he? There is a certain satis- 

 faction in overcoming difficulties and in enduring hard- 

 ships. An easy, contented, assured existence must be 

 monotonous. Is continual struggle better than mo- 

 notony? 



Climate. — Climate is a potent factor in limiting or 

 enforcing natural abilities. In regions where conditions 

 of life are severe men may expend most of their energies 

 in living, but where there is an abundance of food and 

 an easy life is possible, culture may reach a high level 

 of development. Probably the most important climatic 

 factors which influence the attainments of human soci- 

 ties are temperature, humidity, and wind (Barbour, 

 1921). On the wind-swept arctic barrens there are no 

 great cities, no universities or factories. The same is 

 true of the Sahara Desert and of the Amazon Basin. The 

 human race is not at its best where the climate is monot- 

 onous. It makes no difference whether the monotony is 

 cold and bleak, hot and dry, or hot and wet. 



Caucasians and perhaps other races are at their best 

 in the temperate regions. Frequent changes in tempera- 

 ture, humidity, and wind appear to have a tonic effect 



