78 INTRODUCTION. 



Buffon, and the great school of French naturalists, 

 along with thirty years of his own researches, ge- 

 neralised into a natural order that forms its essence : 

 and it is from this source we mean to draw the 

 principal data of the present volume. 



Cuvier did not stop here, he instituted the first 

 regular system of fossil organic remains, which, 

 from the unerring proofs drawn, by comparing the 

 bones of lost species with those of animals now exist- 

 ing, is scrupulously exact in results. He enumerated, 

 by this method, a great number of species of mam- 

 malia that lived in former zoologies, and fixed the 

 laws, whereby a still greater number have since been 

 detected by other naturalists. Of these also we wish 

 to take a cursory notice. 



But although the Baron had achieved such im- 

 portant improvements in zoology, at the time, even 

 so late as when he revised his second edition of the 

 " Animal Kingdom," physiologists had not yet been 

 able to accumulate sufficient observations on the 

 structure and generation of the pouched and mono- 

 treme animals, to justify placing them in a systema- 

 tic order, where it has since appeared to be their 

 most appropriate station. It is true, with every 

 systematist, desirous of classing organic objects, by 

 their affinities, into a natural concatenation ; and, 

 in particular, with mammologists, who begin with 

 man, that although the physical approximations of 

 species form, in general, a continuous chain of suc- 

 cessive modifications from a primal type, taken either 

 in an ascending or descending scale, there are also- 



