14 Where did Life Begin? 



If the amount of sun-heat received at the 

 equator be rated at i,ooo, then, upon the same 

 basis, the average of sun-heat throughout 

 the torrid zone should be rated at 975, the 

 average sun-heat throughout the temperate 

 zones at "j^^j, and the average sun-heat 

 throughout the frigid zones at 454, or less 

 than one-half that of the torrid and less than 

 two-thirds that of the temperate zones. We 

 speak here, and shall hereafter, of the geo- 

 graphical zones of the earth for the sake of 

 convenience. 



The oreatest amount of heat received from 

 the sun and offsetting radiation from the earth, 

 other things being equal, is, of course, as we 

 have seen, at the equator, and less and less 

 every degree north and south of this line to 

 the poles. If, then, the frigid zones have 

 been durinor all this time receivinof the least 

 heat from the sun — the least offset to their 

 own loss of heat by radiation — does it not 

 follow that they were the first parts of the 

 earth sufficiently cooled to maintain vegetal 

 and animal life ? 



The inference seems inevitable. 



