100 Mr. Vigors's Reply to some Observatiom 



If then it be admitted that this formation of genera is an opera- 

 tion of the mind, it follows that the same mental operation which 

 created them can alter or modify them as seems proper. And if 

 the genera of Natural History are founded upon the similitude 

 which the subjects of nature appear in our limited ideas to bear to 

 each other, it is according to the increase of our knowledge 

 respecting them, and the more accurate acquaintance which we are 

 enabled to make with their qualities, that our changes and modifi- 

 cations taost be regulated. 



It is also evident that in the process of generalization the term 

 genus may be philosophically applied to every group of every 

 degree in the series. Particular denominations may, it is true, be 

 applied to the several groups which represent different stages in 

 this process; and when a science or subject becomes complex, 

 such denominations must necessarily be assigned for the purpose of 

 |)ointing out the value of each group as it occupies a higher or a 

 iower rank in the general scale. In Geography, for instance, the 

 different combinations represented by the words County, Province, 

 Kingdom, Empire, &c. ; in Military Tacticks, by Company, 

 Battalion, Brigade, Division, &c. ; in Natural History, by Family, 

 Order, Class, Kingdom, &c., are more definitely pointed out by 

 such terms than if we were to call them genera with numerical 

 or other distinctions. Still such groups, although for the sake of 

 perspicuity, invested with such particular titles, are neither more 

 mor less than genera. We may even again make intermediate 

 stages amidst these already admitted combinations, and we may 

 call them by such names as sections, or subdivisions ; or subking- 

 doms, subclasses, or subgenera; or in short by any other term 

 which appears most appropriate to our purposes : but every such 

 intervening combination will still be found to represent one com- 

 mon nature agreeing to several other common natures, and, as 

 such, it is strictly and logically a genus.* 



* For the reasons assigned above, I have always felt adverse to the use of the 

 term subgenus, although it has been sanctioned by the highest authority. There 

 is a sort of anomaly in the word as generally applied. A subgenus is, strictly 

 speaking, a species ; genus being the proxinaate group to species, according to 

 the usual acceptation of these terms. It is true that all these terms are merery 



