68 ESSAY ON CLASSIFICATION 



not left to study with respect to every species after it is named and 

 classified. No one can read Naumann's Natural History of the Ger- 

 man Birds^^ without feeling that natural history would be much 

 further advanced if the habits of all other animals had been as ac- 

 curately investigated and as minutely recorded; and yet that work 

 contains hardly anything of importance with reference to the sys- 

 tematic arrangement of birds. We scarcely possess the most elemen- 

 tary information necessary to discuss upon a scientific basis the ques- 

 tion of the instincts, and in general the faculties of animals, and to 

 compare them together and with those of man, not only because so 

 few animals have been thoroughly investigated, but because so much 

 fewer still have been watched during their earlier periods of life, 

 when their faculties are first developing; and yet how attractive and 

 instructive this growing age is in every living being! Who, for in- 

 stance, could believe for a moment longer that the habits of animals 

 are in any degree determined by the circumstances under which they 

 live, after having seen a little turtle of the genus Chelydra, still en- 

 closed in its egg-shell, which it hardly fills half-way, with a yolk bag 

 as large as itself hanging from its lower surface and enveloped in its 

 amnios and in its allantois, with the eyes shut, snapping as fiercely 

 as if it could bite without killing itself? Who can watch the Sunfish 

 (Pomotis vulgaris) hovering over its eggs and protecting them for 

 weeks, or the Catfish (Pimelodus Catus) move about with its young, 

 like a hen with her brood, without remaining satisfied that the feel- 

 ing which prompts them in these acts is of the same kind as that 

 which attaches the Cow to her suckling, or the child to its mother? 

 Is there an investigator, who having once recognized such a similar- 

 ity 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 



^ [Johann Andreas Naumann, Naturgeschichte der Vogel Deulsdilands, 7mch eignen 

 Erjahrungen eiilworfeii. Durchaus uingearbeitet . . . von desscn Sohue Jolianti Fried- 

 rich Naumann, 12 vols., Leipzig, 1822-1844]. 



