482 Nomenclature of Divisions 



last contains about fifty groups, each equal to the whole of 

 either of the others. We find in it the terrestrial, the aquatic, 

 and the amphibious ; the carnivorous, the granivorous, and 

 the graminivorous ; the gregarious and the solitary ; the 

 slothful and the active : we find, in fact, in this one order of 

 insects, every variety of form and character discoverable in 

 all the orders of the class Mammalia, let the systematist mul- 

 tiply these as he will. 



The principal object of Mr. Jenyns's remarks seems to be, 

 to depreciate the present mode of subdividing groups ; a 

 mode by which it frequently happens that two groups, for 

 instance, two genera, standing in a catalogue side by side, are 

 evidently of very different value, because the characters by 

 which the more valuable group is defined are generally 

 equally applicable to the less valuable * : as an example, Mr. 

 Jenyns gives Emberiza and Plectrophanes f ; the latter genus 

 being much more confined than the former, and clearly of 

 subordinate value. " Plectrophanes," I quote Mr. Jenyns, 

 " agrees with Emberiza in its most essential characters, but, 

 at the same time, offers one or two peculiarities, by which it is 

 distinguished from the more typical species of that genus." It 

 has a long hind claw, and is, in running, flying, and the form 

 of its wings, essentially a lark : it can, therefore, scarcely be 

 retained in the same genus with the common bunting, the 

 reed bunting, and the yellow-hammer. The next instances 

 are Tetrao, from which Zagopus has been separated ; and 

 Perdix, from which Coturnix has been taken. Zagopus and 

 Coturnix possess the characters of the original groups, but 

 differ in having, in addition, one or two characters which the 

 other species have not. " How, then," says Mr. Jenyns, 

 " with any show of regard to the true principles of classifi- 

 cation, can we consider them," namely, Zagopus, Tetrao, 

 Coturnix, and Perdix, " as so many distinct genera in the 

 family of Tetraonidae ? " How, indeed ! and, to avoid so in- 

 correct an appreciation, the learned writer would, if I under- 

 stand him correctly, consider Tetrao and Perdix as genera, 

 and Zagopus and Cbturnix subgenera of each respectively. 

 Here you observe, Sir, a deviation from harmony is pointed 

 out, and a plan proposed by which to restore that harmony. 

 Let us examine how far this has been done ; how far the dif- 

 ficulty has been conquered. If Perdix is a good and natural 

 genus, and contains twenty species, and one of these species 

 is a good and natural subgenus, and may be with propriety 



* I do not mean to assert that Mr. Jenyns gives this precise reason, but 

 the fact is as I have stated, 

 f Emberiza nivalis L., the snow bunting. 



