t6 



JOURNAL OF THE WILD BIRD IWICSTK lATlOX StlCIETV, 



more palatable than another. The many-banded 

 form would seem to be more abundant in bushy, 

 shaded places, and as the thrushes as a rule 

 prefer open feeding-grounds, it is possible that 

 this mav account for the higher proportion of 

 unhanded shells at certain " anvils." Finally, 

 they find no evidence which would lend support 

 to the view that the young thrushes recognize 

 and crack snail-shells instinctively. On this 

 latter point, however, more extended observa- 

 tions would seem to be desirable. 



THE PART PLAYED BY THE EGG SHELL IN THE 

 FORMATION OF THE CHICKS SKELETON. 



It has long- been known that a fresh fowl's 

 egg contains very little lime, an egg weighing 

 (So gm. has usually not more than 35 mgm. This 

 being so, the question arises, " How does the 

 chick manage to form its skeleton with so small 

 a quantity of lime, and does it obtain a further 

 supplv; if so, where from? " Messrs. Delezennc 

 and Fourneau (.'Xnn. de ITnst. Pasteur, 1918, 

 pp. 413-429) have re-investigated the subject, and 

 after making a large number of experiments, 

 they are led to the following conclusions : — 



(i) The lime in the content of the egg increases 

 about 300 per cent, during the period of incuba- 

 tion. The increase is traceable about the loth 

 and r2th dav, is very marked about the T6th and 

 17th davs, and continues regularly until hatching. 

 (2) In an unfertilized egg put to incubate there 

 is no increase of lime in the egg content. (3) In 

 the egg of the peahen, the increase in lime in the 

 egg content was 500 per cent., and in duck eggs 

 .slightly below 400 per cent. (4) There is no 

 increase of phosphorus during incubation, .'\part 

 therefore from protection, the egg-shell has a 

 phvsiological role, viz., supplying the embryo 

 with a lime reserve. It is thought that by modi- 

 fications of the \-ile11us and albumen during 

 incubation, a substance is set free in determined 

 quantities \\hich has the power of dissolving a 

 definite amount of the lime of the egg-shell. 



WILD BIRDS AND AEROPLANES 



In his i-xidcncc I)erore the Departmental Com- 

 mittee on tlic Protection of Wild Birds, the 

 Minutes of which have recently been published, 

 Lord William Percv suggested that in any future 

 ."^ct, to the prohibition of shooting from a 

 mechanicallv propelled boat, there should be 

 added, " or other vehicle," in order to deal with 



the aeroplane. He continued : "It may not be 

 worth thinking of yet [1914], but it may be very 

 much worth thinking of a very few years hence. 

 It seems to me aeroplanes are going to be a 

 deadly enough factor in driving birds away in any 

 case, and if they were to be used for shooting 

 from, the last hope that birds may get used to 

 them and regard them as harmless nuisances is 

 gone. .Shooting from aeroplanes has already 

 been tried (I know a man who has done it), and 

 there is a letter in this week's Field describing its 

 jovs, so that it is not so far off that it can be 

 ignored ! " 



Captain Gladstone, in his recent book Birds 

 and ihe War, states : " The formation of aero- 

 dromes in various parts of the country had but 

 little effect on the bird population in their 

 vicinity," a statement which does not agree with 

 our own observations. We should like to hear 

 the opinions of members who have made observa- 

 tions on this matter. 



A BIRD BOOK FOR CHILDREN 



Of the manv popular books on birds, not a 

 few are spoilt by inaccurate statements, whilst 

 others are only poor compilations, illustrated 

 with a series of charming photograplis. To 

 neither of these categories does Capt. Pike's 

 recent \nlume, entitled Birdlaud's [.itllr People. 

 belong. The author of Heine Life in Hird- 

 Idii'l believes in seeing nature at first hand. 

 " I liave written and pictured," he says, " what 

 I saw," and his descriptions are as delightful as 

 his photographs. Here are twelve nature studies 

 for children which it would be difficult to improve 

 upon, and many young children, and old ones 

 too, will read this little volume with both pleasure 

 and profit, and will leave it wishing for further 

 aicnunts of Birdland's little people, which we 

 hope will be forthcoming. It is delightfully 

 written, beautifully illustrated, and the printing- 

 lea\cs nothing to' be desired. 



A PLAGUE OF VOLES 



In a recent number of the Gardeners' Clinuiicle 

 Mr. A Trevor Battye calls attention to the plague 

 of \'oles in Hampshire. These rodents appeared 

 in large numbers in 1917 and 1918, but thanks 

 to sea-gulls coming on to the pasture land, and a 

 " quite phenomenal " number of kestrels, they 

 have bei'U held in check. It is in such cases as 

 this, w lien reported upon, that the public arc- 



