[ 265 ] 



XLIII. On Systems and Methods in Natural History, fty 

 J. E. Bicheno, Esq., F.R.S., Sec. L.S., fyc. 



[Concluded from p. 219.] 

 TT was the opinion of Linnaeus, and continues to be the opi- 

 * nion of some of his disciples, that genera are actually founded 

 in nature as much as species. " Naturae opus semper est 

 species et genus." Phil.Bot. § 162. "Genus omne est na- 

 turale, in primordio tale creatum, hinc pro lubitu et secundum 

 cujuscunque theoriam non proterve discindendum aut conglu- 

 tinandum." lb. § 159. So the excellent and elegant author of 

 the " Introduction to Physiological and Systematic Botany," 

 says, " A genus comprehends one or more species so essen- 

 tially different in formation, # nature, and often many adventi- 

 tious qualities from other plants, as to constitute a distinct fa- 

 mily or kind no less permanent, and founded in the immu- 

 table laws of the creation, than the different species of such a 

 genus. Thus in the animal kingdom a horse, ass, and zebra, 

 lorm three species of a very distinct genus, marked not only 

 by its general habit or aspect, its uses and qualities, but also 

 by essential characters in its teeth, hoofs, and internal con- 

 stitution." It was the circumscribing these insulated assem- 

 blages of species that Linnaeus regarded as the business of the 

 accomplished naturalist. 



Those therefore who use the word genus in the Linnaean 

 sense, do not employ it with the same meaning as those who 

 regard genera as merely conventional, and subject to be broken 

 down to suit convenience. The latter would do well to enl- 

 ploy some other term, else one great object will be lost at 

 which we are aiming ; — the keeping together under some one 

 common head those small assemblages of species which in 

 some instances are so obvious, and so important in enabling 

 us to comprehend and discourse of the scheme of nature. 



Whether such insulated groupings really exist, it is for the 

 naturalist to determine, and this can be only inferred from a 

 very extensive knowledge ; but as long as we are witnesses to 



minator as the variable part, as he has himself written it; or without the 

 denominator. Write it how he will, the same egregious blunder still re- 

 mains ; namely, his supposing that every part of the integral must separately 

 satisfy the differential equation. His Postscript is not clear ; but two things 

 may be gathered from it: one, that he is possessed of a method for mea- 

 suring the degrees of absurdity ; the other, that he is not well assured 

 what is, or what is not, Lagrange's method, although he has, twice in this 

 Journal, accused it of failure. The truth is, that all his arguments are di- 

 rected, not peculiarly against Lagrange's method, but against the complete 

 integral, reduced to its simplest form, by whatever method it may have been 

 obtained. , . - 



New Series. Vol. 3. No. 16. April 1828. 2 M such 



