No\t:mber, 1902.] 



KNOWLEDGE 



255 



In the Ibis for April. 1902 (pp. 2tJD-275). Mr. J. H. 

 (Tiirney has a useful article on the three White-fronted 

 Gwse, Anser albifrons, A. erythropiis, and A. (laiiiheU ; 

 while in the Zooluijigf for September, 1902 (pp. 337-o5l), 

 ilr. F. Coburu treats of the same three birds, witli sjieeial 

 remarks upon A. inimheli. Without entering minutely 

 into the (piestion, which would be out of place here, 

 Messrs. Gurney and Coburu give fair evidence for tlieir 

 conclusion that these three geese are specitically distinct, 

 and that tliey all occur in the British Islands. Briefly 

 stated, yl»j-<fr dlhifrons and Anser erythropus inhabit the 

 greater part of Europe and Asia, but ^4. alblfroiix do.'s not 

 go so far north as its near ally. A. albifrons is the White- 

 fronted Goose usually found in Great Britain, while A. 

 enjthropiis was first noticed as a British bird in 1880, and 

 has been procured but seldom since then in this country. 

 Ainier erylhrojiiis is a much smaller bird than A. albifrons, 

 not only in its body but also in its beak, while its plumage 

 is slightly darker, and the white of the face and forehead 

 is more extended than that in .1. albifrons. Anser (janibeli 

 is a North American species, and may be regarded as the 

 New World representative of the White-fronted Geese. It 

 is closely allied to A. albifrons, but may be distinguished 

 from that species by its larger and heavier bill and darker 

 under parts. Besides these differences Mr. Coburu has 

 found that A. gambeli has a considerably longer neck than 

 A. albifrons, a distinction which is made more valuable by 

 his measiu-enicnts having been made from birds in the flesh 

 and not from skins. Mr. Coburu was the first to recognise 

 that Ansvr tjambeli is to be found in the British Islands. 

 The first specimen which drew his attention to the subject 

 was procured in Co. Mayo, and he has since found several 

 others, but all, it appears, from Ireland. However, now that 

 the differences between these three birds have been pointed 

 out, specimens of the supposed A. ijambeli may be found in 

 many collections, and the question thus thoroughly exam- 

 ined. Mr. Coburn gives some valuable descriptions of the 

 various changes of plumage in the two larger White-fronted 

 Geese, but his dogmatic assertions as to liow these changes 

 are effected are supported by insufficient evidence. 



The British Bean-Geese. — Hitherto but two species 

 of Bean-Geese have been recognized in the British Islands, 

 viz., the Pink-footed Goose {Anser brachyrhyncus) and the 

 Bt'iui-Goose (Anser segetnm). In the Field for October 

 ■tth, 1902 (p. 005), Mr. F. W. Frohawk describes how that 

 in figuring the various European geese for M. Serge 

 Al[ihcraky's work on the Geese of Russia, he has found 

 that the true A. segetnm is really very rarely found in this 

 country, and that the bird which is usually so identified is 

 in reality .4 ttser arvensis. Mr. Frohawk does not give the 

 range of the two sj>ecies, but it appears that A. arvensis is 

 by far the commoner bird in p]urope and Asia. The two 

 species differ apparently only in the bills. In arvensis the 

 bill is slightly longer and straighter than that of segetum, 

 while the " nail " of the bill is smaller in j>roportion and 

 more rounded. In colour the liillsof the two birds appear 

 to differ markedly, that of segi-htni being black, with a 

 band of orange between the " nail " and the nostrils, while 

 that of arvensis is almost wholly orange-coloured on its 

 upper portion, while the lower is about one-third orange 

 and two-thirds black. 



Glossy Ibis in the Scilly Islands and in Heke- 

 FORDSHiKE.— We have received two Glossy Ibis for 

 preservation ; one yesterday from the Scilly Isles, and 

 another to-day from Herefoi-dshire. We hear that there 

 were two in the Scilly Isles, but only one obtained. — 

 Pratt & Sons, Brighton, October 15th. 



Cirl Bunting in Ireland. (Zooloqisi. September, 1902, p. .'533.) — 

 Mr. H. E. Howard here records that near Duiifanaghy, Co. Donegal, 

 on August 2nd, he wateliod a Cirl Bunting (Emhcriza cirlusj within 



a few yards. The Cirl Biiiiliug has not been recorded hitherlo in 

 Ireland. 



Ohser rations on the Weii/hls of liirds' Eggs. By N. H. Foster. 

 (Irish Naturalist, October 10O2, pp. 237-2-15.)— The weights and 

 measurements of a number of eggs of 56 species of birds found in 

 Co. Down, Ireland, are given here. 



Increase in the Numbers of Breeding Birds in Mago and Sligo. 

 I5y Robert \\'arren. (Irish Naturalist, October, 1902, pp. 2Ki-2l9.)— 

 Mr. Warren here gives some interesting notes on the increase during 

 the last few years of Starlings, Books, Blackbirds, Shovellers, Shell- 

 drakes, Common Gulls, and Arctic and Lesser Terns in the counties 

 mentioned 



Report on the Movements and Occurrence of Birds in Scotland 

 during 1901. By T. d. Laidlaw. (Annals of Scot. Nat. Hist, 

 pp. 06-82, 129-130, 193-199).— Mr. Laidlaw's annual report of the 

 movements of birds in Scotland is always a careful and useful 

 contribution. 



Oulls killed while following the Plough. (The Annals of 

 Scottish Nat. Hist., October, 1902, p. 251.)— Mr. L. H. Irby records 

 how that in the Island of Coll this .spring four Common Gulls were 

 killed or disabled while closely following a plough by the tilth turned 

 up by the jilough falling back on them. 



Starling Roost on Cramond Island. (The Annals of Scott. Nat. 

 Hist., Oct , 1902, p. 252.)— The Starling roost referred to in IvNOW- 

 i.KDQE for February last, jvage 35, is reported by Mr. Chas. Campbell 

 to he now deserted. A good number of trees have been killed by ihe 

 droppings of the birds, and thesteuch of the place is very disagreeable. 

 Mr. Campbell thinks that the average length of time these birds 

 occujiy a particular roosting place in great numbers is five years. 



All contributions to the column, either in the way of notes 

 or photograph.'!, should be forwarded to Harry F. Witherby, 

 at the Office o/ Knowleuge, 320, High Hidhnrn. Tmndim. 



AsTKOJfOMiCAL. — There can be little doubt that the 

 spectroscope will eventually give precise values of the 

 rotation periods of the planets which have no surfiice 

 markings sufficiently distinct tor the application of the 

 ordinary telescopic method, as it has already done for 

 those parts of the suu which lie outside the spot zones, 

 and for the rings of Saturn. M. Deslandres, of the 

 Meudon Observatory, has given much attention to this 

 v.-ork, and among his latest results is tlie determination 

 that the rotation of the planet Uranus, like the revolution 

 of the satellites, is in a retrograde direction. The method 

 employed is to place the slit of the spectroscope along the 

 equator of the planet, so that the rotation produces an 

 inclination of the lines as compared with those given by a 

 source of liglit which is at rest. 



During the total eclipse of the sun, May 18, 1901, Mr. 

 Perrine, of the Lick Observatory, took advantage of the 

 opportunity of making a photographic search for an intra- 

 Xlercurial planet. After a minute cxamiuation of the 

 negatives, lie now rei)orts that there is lui planetary body 

 as bright as o'O visual magnitude within 18^ of the sun, 

 whose orbit is not inclined more than 7j° to the plane of 

 the sun's equator. Within two-thirds of this region it 

 further ajipcars that there was no such body as briglit as 

 7.f magnitude, unless at the time of eclipse such a hudj' 

 was in direct line with the sun or with the brightest part 

 of the corona. Were there any considerable number of 

 such bodies as bright as 71 magnitude it is probable that 

 some would have been detected. A planetary body of this 

 magnitude would be thirty-four miles in diameter. As 

 seven hundred thousand bodies of this size, and as dense 



