66 GENERAL OENITROLOGY. 



wrong througli the natural faUibility of the mind. The result is, that the " natural classifica- 

 tion," like the elixir of life or the philosopher's stone, is a goal stiU distant ; and as a matter 

 of fact, the present state of the ornithological system is far from being satisfactory. It is 

 obyious that birds, or any other objects, may be "classified" in numberless ways, — in as 

 many ways as are afforded by all their qualities and relations, ^to suit particular purposes, or 

 to satisfy particular bents of mind. Hence have arisen, in the history of the science, very many 

 different schedules of classification ; in fact, nearly every leader of ornithology has in his time 

 proposed his own " system," and enjoyed a more or less respectable and influential following. 

 Systems have been based upon this or that set of characters, and erected from this or that 

 preconception in the mind of the systematist. Down to quite recent days, the modifications 

 of the external parts of birds, particularly of the bill, feet, wings, and tail, were almost ex- 

 clusively employed for purposes of classification; and the mental point of view was, that 

 each species of bfrd was a separate creation, and as much of a fixture in Nature's n,dseuni 

 as any specimen in the natm'alist's cabinet. Crops of classifications have been sown in 

 the fruitful soU of such blind error, but no lasting harvest has been reaped. The confusion 

 thus engendered has brought about the inevitable reaction ; and the fashion of the present 

 day is decidedly the opposite extreme, — that of counting external features of little conse- 

 quence in comparison with anatomical characters. Too much time has been wasted in 

 arguing the superiority of each of these characters for the purposes of classification ; as if 

 a natural classification should not be based upon all points of structure ! as if internal and 

 external characters were not reciprocal and mutually exponent of each other! But the 

 genius of modem taxonomy seems to be so certainly right, — to be tending so surely, even if 

 slo.wly, in the direction of the desired consummation, that all differences of opinion, we may 

 hope, soon will be settled, and defect of knowledge, not perversity of the mind, be the 

 only obstacle left in the way of success. The taxonoinio goal is not now to find the way in 

 which birds may be most conveniently arranged, described, and catalogued ; but to discover 

 their pedigree, and so construct their family-tree. Such a genealogical table, or phylum 

 (Gr. (jiv\ov, phulon, tribe, ra«e, stock), as it is called, is rightly considered the only taxonomy 

 worthy the name, — the only true or natm-al classification. In attempting this end, we proceed 

 upon the belief that, 'as explained above, aU birds, like all other animals and plants, are 

 related to each other genetically, as offspring are to parents ; and that to discover their genetic 

 relationships is to bring out their true affinities, — iu other words, to reconstruct the actual 

 taxonomy of Nature. In this view, there can be but one " natural " classification, to the 

 perfecting of which all increase in our knowledge of the structure of birds infallibly and inevi- 

 tably tends. The classification now in use, or comiug into use, is the result of our best 

 endeavors to accomplish this purpose, and represents what approach we have made to this end. 

 It is one of the great corollaries of that theorem of Evolution which most naturalists are 

 satisfied has been demonstrated. It is necessarily a 



Morphological Classtficatlon ; that is, one based solely upon consideration of structure 

 or form (fiop^rj, morpM, form) ; and for the follovring reasons : Every offspring tends to take 

 on precisely the structure or form of its parents, as its natural physical heritage ; and the 

 principle involved, or the law of heredity, would, if nothing interfered, keep the descendants 

 perfectly true to the physical characters of their progenitors ; they would " breed true " and be 

 exactly alike. But counter infiuences are incessantly operative, in consequence of constantly 

 varying external conditions of environment ; the plasticity of organization of all creatures ren- 

 dering them more or less susceptible of modification by such means, they become unlike their 

 ancestors in various ways and to different degrees. On a large scale is thus accomplished, by 

 natwral selection and other natural agencies, just what man does in a small way in producing 

 and maintaining different breeds of domestic animals. Obviously, amidst such ceaselessly 



