286 THE SCOTTISH NATURALIST 



The above and the amount of emaciation present, might develop 

 within ten days of the infliction of the ijnury." 



A Black-headed Gull (female) found dead on the shore at 

 Balcomie on the 31st of March was also in moult. All over the 

 back and breast were small fresh feathers in quill or half grown. 

 The head had many small feathers coming, and these, with the 

 exception of one or two at the base of the bill which were white, 

 were entirely black — further evidence, if any be needed, in support 

 of Mr Bahr's contention, that the hood is assumed by a moult. 

 This Gull was evidently a bird of the previous year, the tail still 

 having the dark bar at the tip, while the inner secondaries, wing- 

 coverts, and some of the scapulars showed signs of immaturity. In 

 this bird, too, no sign of moult was to be seen on the wings or tail. 

 " There was no evidence of injury ; the upper half of the intestine 

 was crammed with tapeworms, the lower half with large numbers of 

 echinorhincs embedded in mucous membrane." — Leonora Jeffrey 

 RiNTOUL and Evelyn V. Baxter, Largo, Fife. 



The Spring Moult of the Black-headed Gull.— That the 



assumption of the dark hood by Larus ridibundiis in the spring is 

 the result of a moult, and not of a change of colour in the feathers, 

 there can now, I think, be no question. Thirty years ago I 

 obtained the heads of a number of Black-headed Gulls killed on the 

 shores of the Firth of Forth early in spring, and found in every case 

 some of the old white feathers being shed and new black ones 

 making their appearance above the surface of the skin. Other 

 examples in a similar condition have since been examined. 



In his paper on this subject, published in British Birds for 

 September 1909 (vol. iii., p. 105), Dr P. H. Bahr refers to the 

 statement supporting the colour-change theory contained in vol. iii. 

 of the 4th edition of Yarrell's British Birds. As the late Howard 

 Saunders was the editor of that volume, it might be inferred that he 

 was responsible for the statement, or at any rate fully approved of it. 

 The following extract from a letter he wrote me on the subject, 

 dated 20th March 1905, will therefore be read with interest; the 

 letter is a reply to one from me, stating my views, and sending him 

 some of the partially developed black feathers from the head of an 

 adult bird shot on ist March 1905: — "With regard to the head- 

 feathers of L. ridibundus (returned) I have noiv no hesitation in 

 saying that I believe the assumption of the hood is due to new black 

 feathers, the old greyish or white feathers being moulted as having 

 served their time. There is no increase of colour in the individual 

 feathers of the head ; the black is nem). I hereby revoke and 7-ecant 



