202 Proceedings of the Royal Physical Society. 



$ ). The last was a remarkably fine, pink-breasted bird from the neighbour- 

 hood of Musselburgh. A large bill, it will be seen, was not always accompanied 

 by a proportionately longer wing, and vice versa ; in which connection it has 

 to be remembered, of course, that the annual moult takes place in the 

 autumn, so that probably all of the visitors were not in possession of full- 

 grown primaries when they reached us. 



On the basis of Hartert's minimum combination — i.e., wing 75 mm., and 

 bill 9 mm. — for holboclli, I estimate that from a fourth to a third of the birds 

 brought into Edinburgh would be referable to it; and even 10 mm.-billed 

 examples were by no means rare. As already indicated, however, I find it 

 hard, after what I have seen, to believe that they are anything more than 

 large individuals of linaria. Could it have been shown that the larger (on 

 the average) birds occupied distinct breeding-grounds from the smaller ones, 

 a strong case for their separation as geographical races would, no doubt, have 

 been made out ; but at best, such isolation appears only partially to obtain. 

 According to Hartert (op. cit.) A. I. holboclli inhabits the extreme north of the 

 Old and New Worlds, as a rule north of A. I. linaria, in colonies here and 

 there : ; and realising that intermediates between the two do appear to occur, 

 and also that the two sometimes nest in the same locality, he is prompted to 

 ask whether holboclli should not therefore be considered a species instead of 

 a subspecies. To most ornithologists this will not, I imagine, appeal as a 

 satisfactory way out of the difficulty. To my mind the facts, so far as they 

 are at present known, seem rather to point to the existence of a single species 

 exhibiting much individual variation in the matter of size. How this 

 variation is to be accounted for I do not pretend to say. Naturally one 

 wonders if a difference in food has any thing to do with it, and such an ex- 

 planation has, indeed, been put forward. Sundevall adopted the name 

 Fringilla linaria alnorum for the long-beaked birds, believing them to be 

 partial to the seeds of the alder, and F. I. betularum for the short-billed ones from 

 their partiality for the seeds of the birch; while Wolley alleged that the bills 

 were shorter in winter than in summer owing to a change from softer to hard 

 food. 2 My observations on caged lied polls make me doubt if there is much 

 in Wolley's view ; but the subject needs fuller investigation. 



Whatever view we may take of the status of Holboll's Redpoll, we may be 

 sure this is not the first occasion on which it lias occurred in Scotland. The 



1 In the February L91 I No. of British Birds (p. 292), Mr H. F. Witherby states that in 

 Russian Lapland in 18!)9 lie "found both forms with nests on the same breeding-grounds, 

 and shot both forms out of the same little family-parties." 



- ( /. YarrelPs " Brit. Birds," 1th ed., vol. ii. p. 139. 



