48 



NATURE 



[March 21, 1918 



on ascertained facts, and in the main should be 

 devoted to the discovery of a method whereby the 

 infection of the bee by the protozoon Nosema apis 

 can be prevented or remedied, and the test of the 

 success of any experiment to cure an affected 

 colony must include, first, the determination of 

 the presence of the causal organisms ; secondly, 

 the elimination of any other influence; and, finally, 

 the proof of the freedom of the colony from the 

 parasite after a considerable lapse of time. 



, THE DAMAGE TO AGRICULTURE BY 

 VERMIN AND BIRDS. ^ 



THAT farm vermin and certain wild birds annu- 

 ally commit an extraordinary amount of 

 damage to agriculture and agricultural crops has 

 long been recognised, and the need for more care- 

 ful and systematic study of the subject has been 

 frequently dwelt upon in these pages. The per- 

 sonal opinion held by "landowners, sportsmen, 

 farmers, rat-catchers, and naturalists," as well as 

 by a large class of bird-lovers, is really of very 

 little moment. Anyone who has had to sift the 

 evidence obtained from such sources knows how 

 thoroughly untrustworthy and misleading it 

 usually is. It is now universally recognised that a 

 very definite and careful procedure is necessary, 

 carried out by experienced and well-trained 

 workers, if one wishes to arrive at a trustworthy 

 and just conclusion respecting the economic status 

 of any wild animal. 



During part of 1916-17 an inquiry was under- 

 taken upon this subject under the auspices of the 

 Oxford School of Rural Economy in the counties 

 of Oxfordshire and Norfolk. The method of in- 

 quiry will, we feel sure, strike every economic 

 ornithologist, or, indeed, anyone versed in investi- 

 gating the economic status of any wild animal, as 

 peculiar, if not unscientific. The whole of the 

 data here collected are practically obtained from 

 local sources, viz. the opinions of "landowners, 

 sportsmen, farmers, rat-catchers, and naturalists," 

 and innumerable quotations from various news- 

 papers. True, there are a few referejices to the 

 writings of Tegetmeier, Gurney, and others, but 

 the bulk of the work that has been done during the 

 past twelve or fifteen years seems to have been 

 ignored. Surely the conditions existing in the 

 two above-mentioned counties do not differ so 

 materially from those in all other counties as to 

 make the results of such investigations super- 

 fluous to the farmers of Oxfordshire and Norfolk. 



Dr. Gunther would, we feel certain, strongly 

 deprecate such a method in any other biological 

 inquiry. All investigators know how exceedingly 

 difficult it is to arrive at a just conclusion with 

 reference to the feeding habits of any particular 

 species of wild bird and to be able to state defi- 

 nitely whether or not it Is beneficial or injurious. 

 To. weigh the evidence rightly, long experience in 

 such work Is imperative, and whilst the author of 

 this report has no doubt brought together much 



1 " Report .on AKrirultural Damage by Vermin and Birds in the Counties 

 of Norfolk and Oxfordshire in 1916." By R. T. Gunther. Pp. 92. (Oxford 

 University Press, 1917.) Price 2s. M. net. 



NO. 2525, VOL. lOl] 



material that is interesting, It is not such as could 

 be introduced into any scientific inquiry upon the 

 subject, and it carries little, if any, conviction. 



What this correspondent thinks or what that 

 one has seen is really of very little importance, 

 and, so far as the species of wild birds are con- 

 cerned, only a prolonged inquiry, by an experi- 

 enced investigator, upon the data obtained from 

 numerous stomach and crop contents, as well as 

 careful field observations, will ever prove of any 

 practical service. 



The only really valuable Item In the whole report 

 is that with reference to the pheasant, and, curi- 

 ously, this is largely based on the careful Investi- 

 gations of a member of the Cambridge University 

 School of Agriculture, Miss A. F. C.-H. Evershed. 

 The much-maligned pheasant does not support 

 existence upon a diet of- mangels, in spite of 

 weighty statements to the contrary. Miss Ever- 

 shed and others have shown that unless excessive 

 numbers of birds are kept upon a small area, it Is 

 distinctly beneficial to agriculture. Dr. Gunther 

 directs attention to the fact that on some estates 

 where many pheasants are reared there is an 

 absence of wireworm, whereas on others where 

 there are no pheasants, wireworm is found in 

 abundance. 



In many cases the information given Is exceed- 

 ingly scrappy, e.g. in the case of the wild goose, 

 the gull, the crow, the jackdaw, and the lark. As 

 regards the author's conclusions, they do not 

 materially differ from those that have been before 

 the public for some years. We do not think that 

 such reports as these are likely to enhance the 

 reputation of the Oxford School of Rural Eco- 

 nomy In the eyes either of the agriculturist or of 

 the more restricted world of science ; moreover, in 

 our opinion, they are to be deprecated, as the work 

 is based, not on "the solid ground of Nature," but 

 on a loose and very heterogeneous mass of 

 details obtained from sources not always trust- 

 worthy find free from prejudice. 



Finally, If the report were intended for the 

 instruction and benefit of farmers, surely a sum- 

 mary of the results obtained elsewhere, from ex- 

 haustive Inquiries on large numbers of each 

 species, during different months of the year and \ 

 from various counties, should have been given. 

 Walter E. Collinge. 



NOTES. 



From the Scotsman of March 13 we take this in- 

 teresting illustration of the intervention of biological 

 Providence in Scotland. " On a recent week-end there 

 was a remarkable run of salmon in one of the Border 

 rivers. The fish ascended the cauld in large numbers, 

 and in the shallow water on either side it was a 

 matter of no difficulty to seize some of them as they 

 made the passage. The spectacle of so many fish 

 passing to the upper waters led to a general relaxation 

 of the ordinary conditions. On one of the days of 

 the week-end, men, women, and boys could be seen 

 in the water up to the knees and armed with gaffs. 

 The operations of those actively engaged were watched 

 by large crowds on the banks. The natural instinct 

 for capture, aided by the food stringency, became so 



