THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY. 



[SECOND SERIES.] 

 No. 33. SEPTEMBER 1850. 



XIV. — The Natural Relations between Animals and the Elements 

 in which they live. By L. Agassiz*. 



Among the early attempts to arrange animals in a systematic 

 order, we find almost universally, that the natural elements in 

 which their different tribes live are introduced as the funda- 

 mental principle of their classification. During the sixteenth 

 and seventeenth centuries, the great works published upon na- 

 tural 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 the animals themselves, rather than from the external cir- 

 cumstances in which they dwell, had been introduced into our 

 systems, we still find a prevailing influence of such consider- 

 ations upon the circumstances of the natural subdivisions of ani- 

 mals. 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 introduction 

 of this principle was hailed as a new sera in the histoiy of our 

 science ; and after Cuvier had applied it to a general revision of 

 the whole animal kingdom, it was and has been universally ac- 

 knowledged as the only safe foundation of a natural classification 

 of animals. 



The recent progress in zoology, and of the various branches of 

 natural history connected with it, has however opened the pro- 

 spect of further improvements, even upon the basis on which our 

 classification at present rests. For embryology is already dis- 

 playing its vast influence upon zoological questions, and the time 

 is not far distant when its share in the natural arrangement of 

 animals will be as large as that of comparative anatomy itself, 



* From Silliman's American Journal of Science and Arts, No. 27, May 

 1860. 



Ann. l^ Mag. N. Hist. Ser.2. Vol. yi. 11 



