1917-] Letters, Extracts, and Notes. 459 



* British Birds with tlieir Nests and Eggs/ Mr. Frohawk 

 aud. I set aside from our own and other collections no less 

 than twenty-one eggs of Cuculus canorus ; of these the only 

 blue egg was one from Mr. A. B. Farn's collection, expressly 

 stated to have been found in the nest of the Hedge-Sparrow. 

 Mr. William Borrer, of Cowfold, Sussex (with whom I was 

 in correspondence when writing that portion of the work), 

 unless I am very much mistaken, also obtained the blue 

 variety from an Accentor's nest : unfortunately I did not 

 retain the letters which he wrote to me on the subject. 



An e^^ which I found in June 1880 in a Robin's nest 

 was an admirable copy of the eggs of the foster-parent, 

 excepting in the more sharply-defined spotting, a few 

 indistinct lilacine shell-spots and the black dots charac- 

 teristic of many Cuckoos' eggs. Now, considering how 

 very abundant and easy to discover Robins' nests are, I see 

 no reason why reddish Cuckoos' eggs should be rare. 



I quite agree with Major Meiklejohn in rejecting the view 

 that the colouring of Cuckoos' eggs is affected by the food 

 supplied by their foster-parents, and not only for the 

 excellent reason which he gives, but also because so many 

 of the foster-parents supply practically the same food. 

 Of course, we know that Robins, Accentors, Larks, and 

 Pipits eat a good deal of seed, but I do not believe they ever 

 give it to their nestlings, and even the more insectivorous 

 Finches probably feed their young at first only upon half- 

 digested and regurgitated insects and later upon the same 

 food as captured. 



That characteristically coloured Cuckoos' eggs are not 

 always found in appropriate nests will be evident to anyone 

 who examines plate viii. of the eggs in vol. ii. of ' British 

 Birds/ Fig. 271 would have been less conspicuous in a 

 Rock-Pipit^s nest than a Robin's, whereas fig. 272 is 

 palpably intended for the nest of a Chaffinch and not that 

 of a Rock-Pipit ; 299 also is far more characteristic of a 

 Chaffinch than a Hedge-Accentor ; but I do not doubt that 

 if suitable nests had been available, none of these eggs 

 would have been misplaced, for there is strong evidence 



