14 INTRODUCTION. 



the exterior of the animated and inanimate world, and if all must be 

 necessarily ascribed to manifestations of a Divine Power, how shall we 

 appreciate the various intricate natural processes incessantly advancing 

 within that secret laboratory, forming part of the internal system of 

 every living being. 



The purity of the atmosphere would have been of no avail without 

 the means of reaping its benefit by respiration. What utUity could the 

 profusion of food, or the organs for taking it, have afforded without its 

 preparation for nutrition by digestion ? A vast and complex apparatus, 

 physical, mechanical, chemical, all in active operation, has been devised 

 for secretion, solution, combination, and assimilation, to strengthen every 

 corporeal frame, and aid the preservation of life. 



No human invention could either contrive or adapt the multiplicity 

 of organs, and assign their respective functions, as directed singly or 

 united, for the advantage of animated creation. 



Such are the reflections on animated existence, immediately derived 

 from contemplating the fair face of Nature, undisguised by guile. 



Let them receive a fair, just, and candid interpretation, bearing 

 only that weight to which they are entitled, as sustained on ob^'ious 

 facts and reasonable infei'ences. 



Beyond this I have no particular theories to entertain. I make no 

 pretensions to priority of observation : I advance no claim to discovery ; 

 nor do I urge my opinions on the various subjects treated of in these 

 Volumes, otherwise than -with the utmost diffidence. But I could mul- 

 tiply and embellish the numerous facts they contain so much farther, as 

 perhaps to render them more impressive and satisfactory. 



Sedulously interrogating Nature, we shall not be disappointed of 

 responses. 



The following ingredients may be useful to those who propose to 

 prepare corrected views of the Systema Naturce. 



But I wish very earnestly to guard the intelligent reader from ex- 

 pecting a complete history of the living subjects presented before him. 

 This would be an undertaking far surpassing my capacity ; indeed, I be- 



