300 ESSAY ON CLASSIFICATION. 



I shall avail myself of an early opportunity to inves- 

 tigate more fully how far these groups of Vertebrata 

 exhibit such characters as distinguish classes ; and I sub- 

 mit my present impressions upon this subject, rather as 

 suggestions for further researches than as matured results. 



Oo 



SECTION II. 



EAKLY ATTEMPTS TO CLASSIFY ANIMALS. 



So few naturalists have paid special attention to the 

 foundation of the classification of the animal kingdom in 

 general, that I deem it necessary to allude to the differ- 

 ent principles, which, at different times, have guided 

 zoologists in their attempts to group animals according 

 to their natural affinities. This, I hope, will appear the 

 more acceptable, in a work at first published with special 

 reference to the wants of naturalists in America, since 

 few of the libraries of this continent contain even the 

 leading works of our science, and many zealous students 

 are thus prevented from even attempting to make them- 

 selves familiar with what has thus far been done in this 

 direction. 



Science began, in the introduction of names, to de- 

 signate natural groups of different value with the same 

 vagueness which still prevails in ordinary language in the 

 use of class, order, genus, family, species ; taking them 

 either as synonyms or substituting one for the other at 

 random. Linnseus was the first to urge upon naturalists 



Owen has published his invaluable themselves. See OWEN (R.), On the 



paper upon the classification of Mam- Characters, Principles of Division, 



malia, which furnishes most import- and Primary Groups of the Class 



ant new data for a discussion of the Mammalia ; Proceed. Linn. Society, 



true affinities of Mammalia, amouy lfc)57. 



