THE 



EDINBURGH NEW 



PHILOSOPHICAL JOUENAL, 



The Natural Belations between Animals and the Elements in 

 which they Live. By Professor Louis Agassiz.* 



Among the early attempts to arrange animals in a syste- 

 matic order, we find almost universally, that the natural 

 elements in which their different tribes live, are introduced 

 as the fundamental principle of their classification. During 

 the sixteenth and seventeenth centuries, the great works 

 published upon natural history by Gesner, Rondelet, Belon, 

 Aldrovandi, and others, acknowledge this as the only basis 

 of their arrangement of the animal kingdom. Even at a 

 later period, when characters derived from animals them- 

 selves, rather than from the external circumstances in which 

 they dwell, had been introduced into our systems, we still 

 find a prevailing influence of such considerations upon the 

 circumstances of the natural sub-divisions of animals. As 

 soon, however, as the study of comparative anatomy had 

 shed its brilliant light upon this question, those views were 

 entirely abandoned, and the whole animal kingdom was 

 finally arranged according to its internal structure. The in- 

 troduction of this principle was hailed as a new era in the 

 history of our science ; and after Cuvier had applied it to a 

 general revision of the whole animal kingdom, it was, and 

 has been, universally acknowledged as the only safe founda- 

 tion of a natural classification of animals. 



* Silliman's American Journal of Science and Arts, May 1850. See also 

 various papers by Professor Agassiz, read before the American Association for 

 the Advancement of Science for 1849. 



VOL. XLIX. NO. XCVIII. — OCTOBER 1850. N 



