VOL. XV.] LETTERS. 191 



— rather beg the question ? The report which is published yearly 

 by Mr. Witherby includes a note of the numbers of birds marked in 

 the year by each member. This has produced a healthy rivalry, but 

 in order to retain that rivalry there must be permission for each marker 

 to work on those species which in his district are most easily procurable. 

 Having at one time lived near London for some years, in the vicinity 

 of one of the large wooded commons which are over-run each week-end 

 by boys who destroy the nest or take the eggs from any nest which they 

 find, and where only the small warblers are able to bring off their 

 broods successfully, I know how discouraging it would be to the marker 

 who works six days a week in the City, if he were to be restricted to 

 Lapwings, Song-Thrushes, and two or three other species. If he could only 

 mark twenty birds a year his interest would very quickly fall off. If we 

 are asked and encouraged to concentrate on certain species as far as 

 possible, while permission is granted as at present for the marking of 

 other species, the tendency will all be for good. 



Dr. Thomson deprecates promiscuous marking on account of 

 (i) expense, (2) time wasted. The British Birds markers must consider 

 both these aspects. So far as the Magazine is concerned both aspects 

 are measured in terms of money. If each marker is his own judge 

 whether he is wasting his time on unremunerative species, the hkelihood 

 of waste will not be great, he will bear his own penalty and some 

 unforeseen and most interesting record may justify him — -and justify 

 the retention of indiscriminate marking ! 



As regards the expenses of the Scheme, promiscuous marking involves 

 manufacture of more rings, printing of card schedules, provision of 

 filing cabinets, clerical expenses in connection with the issue of rings 

 and sorting of cards. As "unremunerative" species show few 

 recoveries, the cost of recording recoveries will not be materially 

 increased. The following suggestions are made for reducing the 

 financial strain on the Magazine to a minimum : — • 



(a) a charge to be made per 100 rings issued to cover cost of rings, 



cost of schedules, and cost of filing accommodation. Mr, 

 Witherby might tell us what charge would cover expenses. 



(b) Schedules to be filled up in strict numerical order and to be 



sent in only at the end of the summer season, or twice yearly in 

 the case of those who can mark in winter. 



(c) A synopsis of the number of each species marked to be sent in by 



the marker with his schedules in order to save clerical work for 

 the Magazine staff. 



It would stimulate interest if this synopsis were published in the case 

 of some of those who have marked large numbers. 



To obtain homogeneous data for comparison would appear to be 

 impossible unless trained whole time scientists in sufficient numbers 

 are available in the districts selected. This is an ideal which is unat- 

 tainable. The best approximation to the same result will be obtained 

 from an indefinite increase in the number of markers and this can only 

 be brought about by making the scheme popular. To restrict the scope 

 to a few species would tend to make it unpopular and defeat the object 

 to which we are striving to attain. R. O. Blyth. 



(With reference to Mr. Blyth's suggestions numbered (a) (b) and (c). 

 British Birds, with the generous assistance which is provided from time 

 to time by voluntary subscriptions towards the expenses of the scheme, 

 is quite willing to continue to issue rings and schedules without charge. 

 A charge for rings would be unfair, since it would fall heaviest on those 



