60 ESSAY ON CLASSIFICATION. Part I. 



a hen with her brood, without remaining satisfied that the feehng which prompts 

 them in these acts is of the same kind as that which attaches the Cow to her 

 suckhng, or the child to its mother? Who is the investigator, who having once 

 recognized such a similarity between certain faculties of Man and those of the higher 

 animals can feel prepared, in the present stage of our knowledge, to trace the limit 

 where this community of nature ceases? And yet to ascertain the character of all 

 these faculties there is but one road, the study of the habits of animals, and a 

 comparison between them and the earlier stages of development of Man. I confess 

 I could not say in what the mental faculties of a child differ from those of a 

 young Chimpanzee. 



Now that we have physical maps of almost every part of the 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 ascertain 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 mto 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 wdiich animals and 

 j)lants are placed at the time of their creation, within definite limits of action and 

 reaction Ijetween them ; for though not produced by the influence of the physical 

 world, organized beings live in it, they are born in it, they grow up in it, they 

 midtiply 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 sub- 

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

 interesting 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 

 towards 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 



^ Berghaus, Physikalisclier Atlas, Gotlia, 1838 Atlas of Natural FlR'nomena, Edinburgh, 1818, 

 et seq., foL — Johnston, (.\lex. Keith,) Physical 1 vol. fol. 



