INTRODUCTION. 29 



mountains, and the sands of the sea, are replete with 

 life. The waters, too, whether of the ocean or of 

 the land, teem with animated beings. Scarcely is a 

 particle of matter to be fonnd that does not present 

 inhabitants to our view ; and a drop of ditch-water 

 is a little world in itself, stored with inmates of cor- 

 responding magnitude. 



The consideration of the anatomical structure and 

 external conformation of the many thousands of 

 living creatures that come under our view_, would 

 of itself occupy many volumes, were it presented 

 in detail ; and even the simplest outline in which 

 it could be produced would require more space 

 than can be devoted to it here. All departments 

 of Nature are full of wonders ; but this excels the 

 rest in interest, and is proportionally more difficult 

 to be studied ; although men, contented with super- 

 ficial knowledge, may fancy themselves masters of 

 her secrets when they have merely learned to dis- 

 tinguish some hundreds of objects from each other. 



Man, separated from all other animals by pecu- 

 liarities of corporeal organization, not less than by 

 those intellectual faculties which are not in any con- 

 siderable degree participated by the other inhabit- 

 ants of the globe, and who is capable of subsisting 

 in every climate, from the arid regions of the torrid 

 zone to the frozen confines of the poles, also belongs 

 in some measure to the study of nature. But the 

 consideration of man includes a multitude of subjects 

 that do not properly belong to Natural History, in 

 the limited sense in which we use the term. It might 

 even be said that it embraces all human knowledge. 

 Thus, the constitution of the human mind, and the 

 structure of the human body, as well as its healthy 



