FUNDAMENTAL RELATIONS OF ANIMALS 69 



globe,^*^ exhibiting the average temperature of the whole year and 

 of every season upon land and sea; now that the average elevation 

 of the continents above the sea and that of the most characteristic 

 parts of their surface, their valleys, their plains, their table-lands, 

 their mountain systems — are satisfactorily known; now that the 

 distribution of moisture in the atmosphere, the limits of the river 

 systems, the prevailing direction of the winds, the course of the 

 currents of the ocean, are not only investigated, but mapped down, 

 even in school atlases; now that the geological structure of nearly all 

 parts of the globe has been determined with tolerable precision — 

 zoologists have the widest field and the most accurate basis to ascer- 

 tain all the relations which exist between animals and the world 

 in which they live. 



Having thus considered the physical agents with reference to the 

 share they may have had in calling organized beings into existence 

 and satisfied ourselves that they are not the cause of their origin, it 

 now remains for us to examine more particularly these relations as 

 an established fact, as conditions in which animals and plants are 

 placed at the time of their creation, within definite limits of action 

 and reaction between them; for, though not produced by the influ- 

 ence of the physical world, organized beings live in it, they are born 

 in it, they grow up in it, they multiply in it, they assimilate it to 

 themselves or feed upon it, they have even a modifying influence 

 upon it within the same limits, as the physical world is subservient to 

 every manifestation of their life. It cannot fail, therefore, to be highly 

 interestins; and instructive to trace these connections, even without 

 any reference to the manner in which they were established, and this 

 is the proper sphere of investigation in the study of the habits of 

 animals. The behavior of each kind toward its fellow-beings and 

 with reference to the conditions of existence in which it is placed 

 constitutes a field of inquiry of the deepest interest, as extensive as 

 it is complicated. When properly investigated, especially within the 

 sphere which constitutes more particularly the essential character- 

 istics of each species of animals and plants, it is likely to afford the 

 most direct evidence of the unexpected independence of physical 

 influences of organized beings, if I mistake not the evidence I have 



■^Alexander Keith Johnston, The Physical Atlas of Natural Phenomena (Edinburgh, 

 1848). 



