146 WORLD-POWER AND EVOLUTION 



inevitable reflection of the physical circumstances under which 

 mankind evolved. 



In a later chapter we shall follow man's evolution through still 

 another stage, and see how changes of climate seem to have 

 swayed Rome this way and that. Here let us return to the four- 

 teenth century in order to point out certain facts which may be 

 a mere coincidence, but which are at least worth considering in 

 the light of our study of evolution. 



Today the southern storm belt is best developed in Italy. An 

 increase in the intensity of that belt, such as appears to have 

 characterized the Glacial Period, would make itself felt first 

 apparently in that country. Thus at a time like the fourteenth 

 century when great storminess prevailed in northwestern Europe, 

 we should expect that Italy would be stormier than now. The 

 stormy period began with a sudden increase of storminess at the 

 very beginning of the century. This culminated about 1325, but 

 judging by the Big Trees of California the climate did not return 

 to a condition resembling that of today until after 1460.* ( See 

 Figure 24.) Thus the fourteenth century and to a less extent the 

 fifteenth up to 1460 form a period which would be expected to be 

 mentally stimulating in Italy by reason of the comparative 

 storminess and variability. Many of the best authorities hold 

 that during the fourteenth century the mental activity of Italy 

 was higher than at any time since the days of Rome. The Renais- 

 sance, to be sure, did not come till the next century, but its indis- 

 pensable precursor, the Revival of Learning, came in the four- 

 teenth. During the Renaissance the arts of sculpture and paint- 

 ing rose to their highest levels in Leonardo da Vinci and Michael 



*The justification for using the trees of California as a measure of the 

 climate in Italy will be given later. The student should understand that the 

 statement here made is based upon the dotted line given in Figure 72, pp. 

 209 and 231, in "The Climatic Factor." Studies made since that book was 

 written, especially the* study of Owens Lake have shown that the dotted line 

 is probably more correct than the other. They have also shown that during 

 recent decades the curve of storminess appears to be rising. 



