222 VIGNETTES FROM NATURE. 



intuitive insight which are often more valuable 

 after all than any amount of capacity for 

 remembering dry detail ; and he saw many 

 points accordingly which were hidden from 

 the wise and prudent artificial systematists of 

 his time. Organic life, he remarked, must 

 have begun at the Poles. For on the surface 

 of an incandescent planet the Poles would be 

 the first part to cool down sufficiently to allow 

 of the conditions under which alone life 

 becomes possible. This pregnant idea has 

 since been fully developed by later naturalists. 

 Not only is it true that life as a whole must 

 have started at its first beginning from the 

 Pole, but we now know that all fresh waves 

 of fauna or flora must in like manner have 

 set out from the self-same point, and occu- 

 pied the earth by migration in circumpolar 

 zones. Moreover, the great centre of all life 

 was in all probability the North Pole alone, 

 not the South ; for since Mr. Wallace's 

 luminous researches on the geographical dis- 

 tribution of animals, it has become almost 



