Young Cuckoos not Migrating. 75 



accounted for, not by an unusually early arrival, but by the fact 

 that the supposed early visitor was a young bird who failed to 

 migrate at all in the previous autumn, and who survived a mild 

 winter in a sheltered neighbourhood ? 



If this were s<3, it would seem to indicate a failure in instinct, 

 or an incipient variety in instinct, not destined to establish itself 

 under existing conditions, which would not be out of harmony 

 with the apparently somewhat unstable, or at least variable, 

 nature of the instinct of the cuckoo tribe. 



I will try to find out anything more I can about the cuckoos 

 here, where they are exceptionally numerous, so far as my 

 observation goes. 



If you can tell me of any point on which information would be 

 desired, I will try to investigate it. 



With sincere desire to be of any service that lies in my power. 



I remain. 



Yours faithfully, 

 S. C. Freer. 



P.S.^May I add that if you are ever in Salop it would be a 

 great pleasure to me if you could find your way to Ercall. I 

 have nothing indeed in the ornithological line, but have some 

 good American fossils, and a considerable collection of American 

 Indian antiquities, embracing amongst them some rare stone 

 implements, and other ethnological iota. 



Mr. Freer's suggestion that some of the young 

 cuckoos may wholly fail to migrate, is well worth 

 consideration, and has led me to put together possi- 

 bilities — in fact, to frame a kind of theory on the 

 matter. We know that, though the cuckoo prefers 

 for its eggs the nests of insectivorous birds, it never- 

 theless does occasionally — nay more frequently than 

 is believed, drop its eggs into nests of seed or fruit- 

 eating birds ; and that with their feeding the young 

 cuckoos flourish equally well as with the strict insect 

 diet — another remarkable fact. This would do some- 



