Retrospective Criticism. 675 



subjoin the following fact, that came under my observation in the summer 

 of 1829. I had, for two or three days, observed a cuckoo flying about the 

 garden (rather an unusual circumstance), and at the same time a pair of 

 pied wagtails (ikfotacilla alba) constantly following her from one tree to 

 another ; and knowing that a pair of these birds had been in the habit of 

 building their nest, for several years past, in some ivy, I was led to suspect 

 that she had destroyed their eggs ; and, to satisfy myself upon this point, I 

 was induced to take a peep into their nest, and found it contained six 

 eggs, one of which was much superior in size to the rest, and considerably 

 darker, about the size of that of the skylark (Jlauda arvensis L.), but 

 more of an oval shape. I have five of them now in my possession, 

 including the latter, which, I have not the least doubt, is the egg of the 

 cuckoo. In blowing them, for the purpose of placing them in my cabinet, 

 I found that they had been sat upon for three or four days at least, by 

 the appearance of the yolks. I have another egg in my possession, which 

 was taken from the nest of a hedge sparrow (iliotacilla modularis) : with 

 the exception of its being a shade darker, it agrees with the other as 

 to shape and size. The difference is so great between the eggs of the 

 cuckoo and those of the pied wagtail, that I am quite certain that any 

 person with common observation would instantly detect it ; and I venture 

 to suggest to the author of The British Naturalist y to take a peep into all 

 the nests of the pied wagtails, hedge sparrows, titlarks (Jlauda pra- 

 tensis i.), &c. &c., that may happen to come under his observation during, 

 the months of June and July; and I feel quite satisfied that he will, sooner 

 or later, be convinced that all our authors that have written upon this 

 interesting subject, do not err when they state that the cuckoo always 

 deposits her eggs in the nests of other birds, so that their young may be 

 reared by a foster parent. I am. Sir, yours, &c. — J. D. Salmon. Bourne, 

 Lincolnshire, Feb. 16. 1832, 



I have known of three young cuckoos that were reared by pied wagtails, 

 and these in the botanic garden at Bury St. Edmunds : at a future day I 

 will narrate the details. Additional facts on the cuckoo's parasitical habits 

 are presented by Mr. Hoy, in p. 277, 278. — J. D. 



Errors in J. D. Sahnon^s " Fggs and Birds of the Orkney Islands^"* — 

 Sir, Please to correct four errors which appear in my article, p. 415 — 425., 

 and which probably arose from my writing too illegibly. Page 421. line 9. 

 for " scouticurlin " read " scoutiaulin ;" p. 421. line 18. for " syre," read 

 « lyre;" p. 422. line 17. for " dunte," read " dunter;" and p. 423, 

 line 13. for " longer," read " larger." — X B. Salmon. July 9. 1832. 



The Green Humming-bird. — " Rursus in arma feror." Virg. ^neid. 

 " Again I rush to battle." I see, in the last Number, p. 590., that I am 

 accused of abusing Professor Rennie, " through thick and thin," and of 

 treating him " very roughly and unceremoniously." I admit that I have 

 treated him very unceremoniously, to the fullest extent of the word ; but 

 I deny the rest of the accusation. I am surprised that any form of language 

 which I have made use of in the Magazine can be construed into abuse 

 of the Professor, for it never was my intention to abuse him. After this 

 declaration, I shall feel sorry, if the readers of the Magazine do not acquit 

 me of intentionally abusing the worthy Professor " through thick and 

 thin." 



As to my picking out his " little errors," and thus holding up his Orni^ 

 thological Dictionary to " public odium," I plead guilty : but, let me ask, 

 who threw the first stone ? The Professor having found in my Wanderings 

 proof sufficient to answer his purpose, that the humming-bird feeds on 

 insects, wrote a paper for Mr. Loudon's Magazine [Vol. I. p. 371.] on " the 

 food of humming-birds;" and he brought me in, under the character of the 

 " eccentric Waterton," as a witness to his home-spun manufacture. 



X X 2 



