LETM5 



WILD HYBRID BETWEEN HOUSE-SPARROW AND TREE- 

 SPARROW. 

 To the Editors of British Birds. 



Sirs, — In his note on this subject {antea, p. 136), Mr. J. B. Nichols 

 refers to the three examples of this hybrid in a wild state recorded by 

 M. Suchetet in his book. Of these three, only one was actually secured ; 

 and that one, in France. But there are at least two other British 

 records of wild specimens of this hybrid which were obtained. 



One of these birds was secured at Aiglegill in the Lake District in the 

 spring of 1892, and is recorded by the late Rev. H. A. Macpherson at 

 p. Ixxx. of the Prolegomena to his Fauna of Lakeland. This bird was 

 examined by several members of the B.O.U., including Mr. O. V. 

 Aplin, whose description of it is quoted. 



The other was shot on January 13th, 1894, in a farmyard near Bury 

 St. Edmunds, and was exhibited by Mr. J. E. Harting on behalf of the 

 Rev. J. G. Tuck at the meeting of the Linnean Society held on February 

 15th, 1894. It will not escape notice that Bury St. Edmunds is not 

 very far from Colchester, near which Mr. Nichols's specimen was 

 obtained. A. Holte Macpherson. 



Kensington, W. 



WEIGHTS OF CUCKOOS' EGGS. 

 To the Editors of British Birds. 



Sirs, — Referring to Mr. Bunyard's letter on this subject and the 

 Rev. F. C. R. Jourdain's comment thereon {antea, p. 144), it would be 

 unsafe to assume that no Cuckoo ever laid an egg that weighed under 

 160 mg., for there is no reason why a Cuckoo should not (like most 

 other birds), lay a dwarf egg at times, but the size of the egg should 

 always be taken in conjunction with the weight, and this Mr. Jourdain 

 did. The smallest Cuckoo's egg I ever handled weighed 150 mg. and it 

 was distinctly heavy for the size, for had it been the normal size it 

 would have been over the average in weight. As regards this supposed 

 Cuckoo-Chaf&nch there should have been no difficulty in determining 

 its parentage from the texture of the shell alone. 



I give the weights of the 780 eggs of Cuckoo in my collection and for 

 comparison I have taken the British and Continental eggs separately. 



Of the 375 British eggs the minimum is 170 mg. and the maximum 

 290 mg., the average of the 375 being 225.98 mg. ; of the 405 Continental 

 eggs the minimum is 170 mg. and the maximum 295 mg., the average 

 of the 405 being 228.36 mg. ; the average of the 780 eggs is 227.22 mg. 

 It will thus be seen that this average is a long way below that given by 

 Rey. It is well known that British eggs of Cuckoo average less than 

 Continental and I had always been puzzled over Rey's average, knowing 

 that he had a fair number of British eggs in his collection. But on 

 weighing some eggs found with Red-backed Shrikes (Continental), I 

 found that they were above my average, and knowing that Rey had an 

 enormous number of Cuckoos' with Red-backed Shrike I took the 

 weights of my 24 sets of Red-backed Shrike (Continental) and found the 

 average to be 230.625 mg. I think I then found the cause of Rey's 

 231 mg. average. Curiously enough, my maximum British Cuckoo 

 egg (290 mg.) was found in the nest of a Red-backed Shrike. 

 DiDSBURY. Herbert Massey 



