758 UNITY OF ORGANIZATION. 



4. But that as the temperature of the globe is 

 diversified by the inclination of its axis, the un- 

 equal distribution of land and sea, mountains 

 and valleys, dense forests and sandy plains, there 

 is a corresponding variety of colour, form, fea- 

 tures, and whole organization of the human spe- 

 cies, multiplied by the mixture of nations, tribes, 

 and families by conquests, migrations, and inter- 

 marriages. 



The truth is, that if caloric be the organizing 

 principle throughout nature, it must determine 

 all the various degrees and modes of action, on 

 which every diversity in the structure of plants 

 and animals depends, that as all the organs are 

 formed by the nutritive process, the rapidity of 

 which is in proportion to the amount of respira- 

 tion, they are more fully developed in warm than 

 in cold blooded animals, modified, however, by 

 climate, or external temperature, nature of the 

 surrounding medium, and the various circum- 

 stances which tend to augment the growth of 

 some one or more organs, and to suppress that of 

 others, as shewn by the numerous diversities of 

 form, size, intelligence, &c. among animals be- 

 longing to the same genus and species. 



Moreover, it has been ascertained by the re- 

 searches of Lamarck, St. Hilaire, and other emi- 

 nent physiologists of France, whose views have 

 been adopted by Dr. Grant, that all the animals 

 enumerated by naturalists (amounting to about 



