in Natural History. 267 



and when they are so multiplied, it may be suspected that 

 many of them are arbitrary and artificial. This attempt at 

 breaking down good orders and genera into many subordinate 

 and loosely defined groups, and encumbering them with names, 

 involves the subject in obscurity, and may well be questioned 

 as contrary to his main design of presenting those compre- 

 hensive views which are afforded by a natural system. 



Mr. Brown has adopted a different mode in his Prodromus. 

 He has attempted to combine no further than his knowledge 

 w r ould warrant, not even employing the terms class or order as 

 the names of his groups. As his object is chiefly synthesis, he 

 keeps his diagnostic characters apart, thus leaving the mind 

 less embarrassed when it is in pursuit of analysis. It must be 

 admitted indeed, that his work cannot be employed with any 

 success by the inexperienced, or even by those who have oc- 

 cupied themselves only in searching for species ; but to have 

 made it subservient to this purpose, would have been to have 

 rendered it less beautiful and complete as a work of synthesis. 

 His aphorisms and remarks not being reduced to exact me- 

 thod, " are," as Lord Bacon expresses it, " still in their growth, 

 increasing in bulk and substance." 



Now wherever the object of the systematist is to enable his 

 reader to discover species, it is necessary to define at every 

 step ; and where natural characters do' not present themselves, 

 we must adopt artificial ones. For this purpose large classes 

 are formed, many of which are necessarily artificial. These 

 again are broken up into orders, mostly of an artificial cha- 

 racter; and thus the naturalist is led step by step from more 

 comprehensive definitions to less, from class to order, from 

 order to genus, and from genus to species. In this descend- 

 ing series it will be observed that the essential feature is the 

 facility that is afforded for definition. Hence the Linnaean 

 system of botany has succeeded so well, because its author se- 

 lected chiefly as the ground of his arrangement the number 

 and proportion of parts most obvious and least liable to vary. 

 His classes and orders are avowedly so many assumptions, 

 which practice has shown to be convenient; but when we come to 

 genera, the artificial system falls in with the natural, as Linnaeus 

 framed their characters upon resemblances founded in nature. 



Now in the natural system this machinery of terms cannot 

 be employed in the same manner. It is an ascending series 

 from the less to the greater predicate. From genera we pro- 

 ceed upwards to orders, and orders we combine into classes. 

 We become more and more general in our characters, instead 

 of more and more definite. Here indeed we ought not to sa- 

 crifice, as in the artificial scheme, to convenience ; and break 



2 M 2 up 



