200 Proceedings of the Royal Physical Society. 



" The most astonishing migration en masse", he there writes, "of this species 

 which I have ever witnessed took place in the autumn of 1847. This migration, 

 I believe, extended over the whole of Germany. It commenced here on the 13th 

 of October with from twenty to thirty examples, its numbers increasing daily 

 until, from the 26th of October until the 3rd of November, they are recorded as 

 hundreds daily in my diary ; on the 4th and 5th November, ' countless flocks ' and 

 'innumerable multitudes' are noted; on the 6th, 'fewer than on previous day.' 

 About a hundred each day occurred until the middle of the month, after which 

 time solitary individuals and smaller companies continued to be seen until the 

 middle of February of the following year. On the two principal days above 

 mentioned, the whole island was literally covered with these birds, so that one 

 might have thrown a stone in any direction one chose, and it was sure to hit birds 

 as long as it continued rolling along the ground." 



The Mealy Redpoll is a characteristic bird of the birch woods of the 

 northern regions of both hemispheres. In Europe it is a native of Scandinavia 

 and Northern Kussia, breeding from about the latitude of Christiania to the 

 extreme limit of the birch growth, and in the main wintering, one gathers, 

 within these bounds. From Professor Collett's " Bird-Life in Arctic 

 Norway," 1 for instance, we learn that as far north as Tromso, where it is 

 particularly numerous in the summer-time, some are to be met with in the 

 birch woods during winter also ; while according to Wheelwright many winter 

 in Lapland. 2 To what the large-scale migrations that from time to time take 

 place are due, I am not prepared to say. Exceptional climatic conditions, 

 failure of food-supply, abnormal increase in the number of the birds owing 

 to favourable breeding seasons, are probable causes that naturally occur to 

 one ; but, so far as I know, there are no data by which to test the matter. 



On looking at the cagefuls of Mealy Redpolls in the dealers' shops at the 

 time of the recent invasion, one could not help noticing how much they 

 varied in size. Some were scarcely larger than Lesser Redpolls (A. rufescens), 

 of which a considerable number had also been taken, while others were as 

 large as Linnets ; and between these extremes every gradation could be 

 observed. In view of the wealth of racial forms into which the Redpolls 

 have been divided by experts, I was on the outlook for examples differing 

 from the type, light-coloured birds with white unstreaked rump and under 

 tail-coverts — the Greenland Redpoll (Acanlhis homemanni) and the Hoary 

 or Coues's Redpoll (A. h. cxilipci) — being especially in my mind. 3 Apart 

 from the rose-pink on the breasts of many of the males, the only difference 



1 English edition, 1894, p. 13. 



2 " A Spring and Summer in Lapland," 1871, p. 209 ; see also p. 10. 



; Exilipes occurred at Fair Isle (Eagle Clarke, A.ti.NJT., January 1911, p. 53) ; and 1 



.•mi In]. I .mi' was caught at Montrose, but so fat no proof has been produced. Another 

 is supposed to have been taken in Norfolk {cj. Cayc Birds of lltli March 1011). 



