Ornithology of Siberia. 427 



the change would be said to be protective ; and where it con- 

 trasted with them, it would be ascribed to sexual selection. 

 No doubt in some instances the male Siberian bird does 

 differ from his relation in Western Europe more than their 

 respective females do ; but I am not aware of any evidence to 

 prove that the oriental taste for rich colour is shared by the 

 bipeds with feathers with the bipeds without feathers. I am 

 inclined to ascribe the differences under consideration rather 

 to the direct influence of climate, which may have a chemical 

 action on the colouring-matter of the feathers, in the absence 

 of natural sexual relations to interfere with its operation. 

 But whatever the cause may be, the effects are great orni- 

 thological facts, which can no longer be ignored by the 

 student ; and our system of nomenclature must be made to 

 recognize them at any cost, even if its binomial character 

 has to be modified for the purpose. Probably the simplest 

 course will be to give binomial names to the two extreme 

 forms, whether the difference between them be specific or 

 subspecific, and to reserve the trinomial nomenclature for 

 the intermediate forms which must exist in the latter case. 

 No doubt such a system increases the number of names with 

 which the memory has to be burdened, and fails to show the 

 relationship of nearly allied species. It is high time, how- 

 ever, that ornithologists came to some mutual understanding 

 on this question. Are we in the future going to discriminate 

 between the two forms of the Great Spotted Woodpecker or 

 not ? And if we are, what system are we going to adopt ? 

 In this paper I have called them respectively 



Picus major, 



Picus cissa. 

 The American plan would be to call them 



Picus major, 



Picus major, var. cissa. 

 An improvement upon this would be 



k Picus major (typicus) , 



Picus major (arcticus}. 

 A.t present we either do not discriminate them at all, like 



