il/r. Vigors and Dr. IIousfield o)i Australian Birds. 171 



try have so long and so Justly followed. But nothing can be more 

 unfounded than such a supposition. Devoted as our leading zoo- 

 logists have hitherto been to Linnœus, they have not evinced a 

 more sincere attachment to his precepts than the authors of the 

 following Catalogue. In point of fact, the apparent deviation 

 from the " Systema Naturce," in our attempt to arrange the 

 ornithology of New Holland, and in similar undertakings of the 

 present day, will be found, when strictly investigated, to be 

 more in word than in reality. It would be superfluous to call 

 to the recollection of the Society how important has been the 

 increase of knowledge in every branch of natural history since 

 the days of Linnœus. That increase, in the particular depart- 

 ment upon which we have entered, rendering the subjects even 

 now above five times more extensive than when that pre-eminent 

 naturalist undertook to arrange them, has raised his subordinate 

 groups into groups of a considerably higher value than they 

 originally possessed. Those divisions which he instituted as the 

 next superior groups to species, and which he denominated 

 genera, have swelled out by the vast accumulation of species 

 and the endless variety of new forms comprised in them, into 

 what are now considered families, or into assemblages of even 

 still more extensive signification. In such a change of materials, 

 a corresponding change in their denominations appears essen- 

 tially necessary : the groups, which were once termed genera, 

 require a more comprehensive title ; and the before-unnoticed 

 modifications of form that spring up and constitute subordinate 

 groups among them take the place which they have left, and, 

 assuming the rank, demand the name, of genera. Such, in fact, 

 is the natural course of our science ; and such will ever be its 

 progress, while information continues to increase. 



On our turnino- to the examination, however, of the original 

 groups of Linnaeus, limited as they confessedly were in his days 



z 2 as 



