426 Mr. H. Seebohm on the 



of science. In the majority of cases, however, the writers 

 have never seen a Siberian skin, and Pallas's names have 

 been enrolled in the list of synonyms without note or com- 

 ment. A fertile cause of this neglect is to be found in a 

 blind adherence to the binomial system of nomenclature. 

 It is time that the study of ornithology should be freed from 

 the red tape which the antiquated philosophers of the British 

 Association have wound around it. With these writers a 

 variation is either specific or it is nothing. They attempt to 

 draw a line where nature has drawn none. Their dogmatic 

 criticism of Pallas' s species, " we consider this a good species," 

 or " we cannot admit the validity of this species," reads, in 

 the light which the theory of evolution has thrown upon these 

 questions, like a satire upon their own ignorance. The fact 

 that for more than a century a binomial system of nomen- 

 clature has been more or less rigidly adopted by ornithologists 

 is an obscure circumstance of comparative small moment; 

 but the fact that, for example, the Nuthatch of Western and 

 Southern Europe is represented in Scandinavia by a semi- 

 arctic form modified by the influence of the Gulf-stream, and 

 that eastwards a truly arctic form occurs, which, in the 

 valley of the Amoor, again becomes semiarctic, but of a 

 different type from the western semiarctic form, whilst in 

 China the South-European form reoccurs on a somewhat 

 smaller scale, and in the mountains of Assam the western 

 semiarctic form is also reproduced on a slightly smaller scale, 

 is a fact, or rather a series of facts, of the deepest interest to 

 the student ; and if the binomial system of nomenclature can- 

 not be adapted so as to catalogue these facts in a proper 

 manner, then the sooner the binomial system of nomencla- 

 ture is cast to the dogs the better. 



The fact remains that many Siberian birds which are 

 common to Europe do present marked differences in colour, 

 not only amongst resident birds, but also amongst migrants. 

 The colours of the Siberian birds are more pronounced, the 

 blacks are blacker and the whites are whiter. Darwin would 

 doubtless explain these facts on two hypotheses. Where the 

 change of colour resembled that of the surrounding objects, 



