FRANCIS W1LLUGHBY. 29 



isted from a remote period among civilized nations. 

 But, carried to this extent only, Natural History 

 consists in mere amusement, and the books and 

 pictures serving merely this purpose, may afford 

 relaxation from more important studies, or at 

 best supply the naturalist engaged in the forma- 

 tion or study of a system with useful descriptions 

 of such individual creatures as may be inacces- 

 sible to his own observation. 



Yet, in nearly this state did Natural History 

 continue till the time of Aristotle, at least among 

 such portions of mankind as were unacquainted 

 with the Scriptures, and for many ages after him. 

 The scientific pursuit of any department of 

 Natural History supposes classification, or the 

 arrangement of its various objects into those 

 divisions called genera and species, an arrange- 

 ment founded on some selected points of agree- 

 ment between those objects. 



The most general, because the most obvious 

 point of agreement, would be a complete identity 

 among different indi vid uals. Thus, to take a familiar 

 illustration from ornithology, a certain bird being 

 called a crow, the same name or noun is given to 

 every other crow in the flock, which general 

 name or noun is technically called the genus. 

 Among the different tribes of creatures, however, 

 the resemblance, though very close, is not com- 

 plete, the difference sometimes consisting in but 

 few subordinate variations, sometimes only in 

 one ; in such cases, the naturalist considers to 

 which genus any given instance of variation 



