APPENDIX TO OSCINES. 227 



that, the oxaraination of a large number of spocimons has resulted ia his accoptiao; a 

 luHch smaller number of species than hud previously liui-u receivetl as valid, and sig- 

 nificantly adds that, had a still more complete seriLS lieeu before liim, he would iirobably 

 have reduced the number still further. So tbeu, lu his mind, recoguitiou of specihc 

 rank is something almost dependent upon the nuraLier of specimens one has for com- 

 parison — the larger the series, the fewer the species.* Another equally well-known 

 author, iu a recent review of the tifteeu species of the genus CerihioJa, remarks that " it 

 is a nice question what are really species in this genus, and what merely races or varie- 

 ties, but it would probably be not far from correct to assume that the various forms 

 described are simply modifications of one primitive species, produced by geographical 

 distribution and external physical conditions." Is there any reason to .'5iippose that, 

 since the primitive species has become thus modiBcd by geographical distribution and 

 external physical conditions, that it was not, itself, one of the modiiiuationa of a still 

 more primitive form? Yet the progenitors of this " primitive species," which has split 

 into no less than fifteen different races, must have undergone variations brought about 

 by changed geographical habitats aud different physical conditions; unless, indeed, 

 they were special creations, and confined to a single narrow locality, a suppo-iitiou 

 which we have quite as much reason for applying to all the recent forms of Cerlkiola as 

 to the one original form. 



In considering the question of specific distinction, too little importance has been 

 attached to the habits and notes of the difi'erent races, while there seems to be no iu- 

 trinsio reason why a difierence in these points should not be considered of as much weight 

 as a variation in the plumage. A series of Meadow-larks may be laid out, represent- 

 ing a gradual transition between the Eastern and Western forms, yet the notes of the 

 two are so different that, in a region where they both abound, either may be distin- 

 guished at once by its voice ; and a bird whose soug is intermediate between the two, 

 is so rare that, in a residence of two years in a region where both were abundaut, I 

 never heard one. Here, then, is an instance where the different forms may always be 

 distinguished by their notes, though sometimes ambiguous in their plumage. Again, 

 Contopus rickardsonii vesemhles Sayornis fiiscus in its habits more than it does the Wood 

 Pewee, C. lireiis, while its notes are as different from those of the latter bird as the 

 western Lark's are from the eastern's. If Macgillivray's Warbler is a geographicail 

 variety of the Monrning Warbler, it is difficult to comprehend how it could have suf- 

 fered such a complete loss of musical power, seeing that its habits are unchanged, and 

 that the external physical influences are very nearly similar. Perhaps, however, the 

 "dry, thin air" can account for it; but if this is the case, it would be interesting to 

 know why the same air has failed to change the voices of the Eobiu and Hermit Thrush 

 in the slightest degree, t AU the western species which are closely allied ro, or inter- 

 grade with eastern forms, vary from the latter, more or less, in their notes aud habits, 

 sometimes so much that a resemblance can scarcely be recognized. That this may be 

 partly due to changed conditions of life, is undeniable, yet, under the supposition that 

 it has been wholly brought about by such cause, it is very difficult to see why the same 

 changes have effected opposite results in birds of the same family aud of the same mode 

 of life. And if these supposed races are found to meet and occupy the same regions, 

 each preserving its peculiarities of notes, plumage, and habits, with a great degree of 

 constancy, how can they properly be called "geographical" varieties, or their differ- 

 ences be accounted for on the supposition of difi'erent physical conditions ? Yet of one 

 species, at least {SturneUa magna), this is absolutely true. And admitting the in- 

 fluence of these external causes to be sufficient to produce such results, the question at 

 once arises: How wide must be the gap that separates congeneric "species;" where 

 shall the limit of variation produced by such causes be placed ? 



But however ornithologists may differ as to the proper rank of these forms, their 

 existence is undeniable, whether classed as species, varieties, or races, and it becomes 

 necessary to distinguish them apart in ornithological nomenclature. The usual method 

 is to give the name of the first-discovered race, together with the specific title of the 

 form referred to as a variety. Thus, Macgillivray's Warbler is spoken of as Geothli/pia 

 Philadelphia var. macgillivrayi. To follow out this method, every bird of which there is 

 more than a single form should be designated by tLreet r.ames, generic, specific, and 



* Quite true. We can only predicate and define species at all from the mere circum- 

 stance of missing links. " Species" are the twigs of a tree separated from the parent 

 stem. We name and arrange them arbitrarily, in default of a means of reconstructing 

 the whole tree according to nature's ramificatious. — E. C. 



tis it not quite reasonable to suppose that different animals may possess a different 

 degree of susceptibility to modifying influences, and that some may be able to resist 

 such influences altogether ? We must not presume upon uniform plastictity of organi- 

 zation. — E. C. 



tl strongly advocate a return to polynomial nomenclature, as the only fit instru- 

 ment of expression of nice shades of zoological meaning. Many of us, in efi'ect, are 

 already using trinomials, the true nature of which is but partially concealed by inter- 

 vention of the term " var." — E. C. 



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