130 ARON. 



influence of the tropical sun acquires temperatures far above those com- 

 patible with life. 



7. It is demonstrated that in the tropical sun a man with a colored 

 skin is in- a better position as regards heat regulation than is a man 

 with a white skin. 



8. Types of apparatus suitable for testing temperatures thermo- 

 electrically are described. 



In concluding, I wish to invite attention to more general biologic 

 questions as regards climate. The monkey, whose home is in the 

 Tropics, withstands the sun less readily than any other animal I have 

 observed, including even the white man. Of course, the monkey does 

 not live in the fields; his home is in the forest, into which only a small 

 proportion of the direct rays of the sun can enter. He instinctively 

 avoids exposing himself to the sun for more than a few minutes. The 

 same is true of the native of the Tropics, if he is left to his own cus- 

 toms. Even if he is otherwise nearly naked, he often wears a large 

 hat-like arrangement which shades not only his head but his body. 



Certain features of any climate must always be met. The temperate 

 climate is only suitable for man if he protects his body against it. 

 Our chemical heat regulation would not be sufficient to allow us to with- 

 stand the cold of temperate climates without the protection of clothes 

 and houses. 



The question of the best way to live in a certain climate will always 

 be to learn how to avoid its injurious effects, or to secure protection 

 against them. No better example than the monkey, which is killed by 

 the tropical sun in from one to two hours, can be found to confirm 

 the above statements. 



