Letters, Extracts:, and Notes. 639 



The Black-thkoated and Black-eared Wheatears. 



Sir,— In tlie Bulletin of the B. O. C. for the March 

 meeting, p. 89, I notice that Dr. Hartert invites a dis- 

 cussion on the question of the sjiecific distinctness of the 

 Black-throated and Black-eared Wheatear, giving five main 

 reasons why they should be considered as one species having 

 a dimorphic phase in the males. The facts as he states them 

 are obviously correct, and hence, presuming there is no 

 further evidence at hand, the subject becomes merely one 

 of opinion. The main question of importance in this case 

 seems to me to be not so much whether they are or are not 

 the same species, but how a certain group of birds showing 

 in the males very obvious and well-maiked differences, 

 n)ay be most conveniently distinguished. The chief object 

 of all systematic work should be to so arrange and name the 

 various varieties and forms of animal life that they may 

 be conveniently classified and recognised without having 

 recourse to long and verbose descriptions. To consider 

 these two forms as one species is therefore simply to prove 

 a very plain and obvious fact, so that if I was only to find 

 Black-throated males in one locality, I should not be able 

 to convey the fact without going into a description. That 

 being so, it becomes necessary to consider by what accepted 

 means of classification they can be named. They cannot be 

 designated by simple trinomials as (save in very exceptional 

 cases) a trinomial implies a geographical vai^iety, and two 

 geographical varieties cannot have the same breeding area. 

 If they are considered as the same species, we have to fall 

 back on the cumbersome quadrinomial, viz., (Enanthe h. 



Mspanica var , which is the only logical solution 



if they are considered as the same species ; if, however, 

 we consider them as two different species, all difficulties 

 disappear. 



Is there any absolute proof that they are one species ? 

 Before we can answer that, we must, I think, try and define 

 a species. We all know, or think we know, what a species 

 is, but I have met nobodv vet who could give an accurate 



