EiDcnvAY on Zoological Nomenclature,. 131 



(Linn.) ceases to have a definite meaning, and the reader must 

 always be in doubt as to whether a bird so described be the Saxi- 

 cola stajyazitia of Linnteus, apnd Latham, Vieillot, Teiuminck, and 

 a host of other authors, or the Saxicola stapazina of Linnaeus, apiid 

 Dresser, — two totally distinct birds. At all costs scientific accu- 

 racy must be preserved, and I see no possible alternative but to 

 complicate our ornithological nomenclature still further, by calling 

 the Black-eared Chat Saxicola sta2jazina (Linn.) et Dresser. 



" It would be well for the simplicity of ornithological nomen- 

 clature if its complications could even stop here. From the days 

 of Linnaeus to those of Wallace and Darwin, most ornithologists 

 were agreed that species were divided by a hard and fivst line, and 

 that the difficulty which the student had to surmount was the dis- 

 covery of the lines of demarcation which Nature herself had drawn 

 between the various specially created species. Now that most sci- 

 entific ornithologists have adopted the theory that these hard and 

 fiist lines seldom exist in nature ; that species were not specially 

 created, but were gradually developed according to certain more or 

 less knoW'U fixed laws ; and that consequently there must be at any 

 one period of the world's history a large number of species in pi'o- 

 cess of differentiation, our difficulties are largely increased. The 

 question naturally arises, What is a species 1 We must either draw 

 an artificially hard and fast line where Natui'e has drawn none, or 

 we must accept Nature as she is, and make the best of the compli- 

 cations which necessarily arise in our nomenclature in attempting 

 to harmonize it with f\icts which we cannot, as scientific students, 

 ignore. Hence, it appears to me to be absolutely necessary for 

 modern ornithologists to recognize the existence of subspecies, — 

 that is, species in the process of difterentiation, incipient species, 

 where the intermediate forms have not yet died out, but where a 

 series gradually leading ft-om one extreme to the other may be ob- 

 tained. I fully recognize the danger of such a practice. It is easy 

 to imagine the abuses of which it is capable. Inexperienced orni- 

 thologists will be tempted to think that differences of age, sex, and 

 season, to say nothing of accidental individual variations, are inter- 

 mediate forms worthy of the rank of a subspecies ; and our nomen- 

 clature may run the risk of being still more flooded with names as 

 injurious as the useless synonyms of the elder Brehm. I am, how- 

 ever, of the opinion that these difficulties will have, sooner or later, 

 to be faced. It seems to rae that the scientific ornithologist cannot 



