Mr. Vigors's Repli/ to some Observations 96 



their respective orders; that is, between the Strix and a typical 

 species of Falco^ and between the Caprimulgus and a species of 

 Corvus or of Motacilla. In fact our arrangements of natural objects 

 are now founded upon the principle that there are no divisions in 

 nature; and all our nominal divisions are merely mental assump- 

 tions adopted for the sake of convenience. They imply that the 

 mind can keep certain assemblages apart in its conceptions, by 

 fixing upon certain typical modifications of form ; but the names 

 affixed to these assemblages, and the arbitrary limits assigned them 

 in no wise infer an actual separation between them. 



The very objection which has been subsequently brought for- 

 ward in the " Dictwniiaire" against the subdivisions of the 

 Psittacidce, that they have been previously pointed out by antece- 

 dent w Titers, would, if true, prove that even in the writer's mind 

 the subdivision of a natural group does not infer an unnatural 

 separation. These subdivisions of the French naturalists to which 

 he alludes are noticed by him with every commendation ; and we 

 hear no complaints of their introducing any breach of affinity in 

 " the natural group" of Psittacus. It is true that these latter 

 subdivisions are called sections and have French names assigned 

 them, while mine are denominated genera, and have Latin or 

 scientilick names of distinction. But whatever may be the value 

 of the denomination given to the group, or whatever may be the 

 Iangua£;e from which the particular name of it is derived, the 

 principle which regulates the subdivision is still the same. If there 

 be no difference between the groups themselves, it would be the 

 height of absurdity to suppose that a greater infringement upon 

 the laws of arrangement, as far as they regard affinity, would take 

 place when these groups are called genera, than when they are 

 distinguished by the name of sections. 



But we must come more closely to this point. In all the other 

 Linnean genera, such as those subdivided groups to which I have 

 alluded above, there seems to have been no hesitation in calling 

 the subdivisions genera. Many of these groups are by no means so 

 copious in species as Psittacus^ which it is to be remembered, con- 

 tains two hundred and twenty-four species, according to the 

 M riter in the " Dictionnaire,^^ Why the subdivisions in the group 



