Ha THE NEW EVOLUTION 



abundant in the tropics, while in the sea, due to con- 

 servation by indefinite preservation, they are most 

 abundant in the coldest water. 



The regions supporting the greatest density of life 

 both on the land and in the sea are the regions show- 

 ing the least deviation from the optimum conditions. 

 Naturally in the regions showing the least deviation 

 from the optimum conditions there is the least incen- 

 tive to or necessity for variety among the endemic 

 types of plants and animals. Therefore the regions 

 wherein is to be found the greatest density of life are 

 not the regions where animals and plants occur in 

 the maximum variety. The greatest variety both in 

 plants and animals is to be found in regions where 

 there are the most diversified conditions to be met 

 which may be met through minor adaptations. 



Conditions which involve the passage by animals 

 and plants through a resting stage, more or less pro- 

 longed, necessitate what might be termed major adap- 

 tations. For an enforced resting stage necessitates 

 ability to prepare for it, or to recover from it, or for 

 both previous preparation and subsequent recovery. 



The necessity for such major adaptations renders 

 life impossible for many types which are quite capable 

 of meeting the requirements for minor adaptations, 

 as for instance those called for to counteract daily 

 variations in the essentials for existence. 



The fact that minor adaptations may take many dif- 

 ferent forms whereas the possible variety in major 

 adaptations is rather closely circumscribed furnishes 

 the explanation of the interesting fact that the great- 



