white tip, and is much whiter towards the base, the difference being quite as perceptible on the outer as on the inner web. The seventh has a small spot of brown towards the tip on the outer web, the rest of the feather being almost uniform pale grey, with a slightly darker shade on the outer web, and white at the tip; the eighth grey, with a broad white tip. In No. 2 the fifth primary has no white tip; the sixth also has no white tip, and not so much white towards the base; the seventh is all brown, slightly mottled towards the base, and only a very slight indication of a white tip; and the eighth is mottled throughout. I think it worth while to mention these two birds, as I have their exact dates, and the difference of a year between them agrees exactly with young birds which I have taken in their first feathers and brought up tame. I may also add, with regard to change of plumage owing to age, that very old birds do not appear to get their heads so much streaked with brown in the winter as younger though still adult birds, as a pair which I caught in Sark when only flappers, and brought home in July, 1866, had few or no brown streaks about their heads in the winter of 1877-8, and in the winter of 1878-9 their heads are almost as white as in the breeding-season. These birds had their first brood in 1873, and have bred regularly every year since that time, and certainly have considerably more white on their primary quills than when they first assumed adult plumage and began to breed. Probably this increase of white on the primaries as age increases, even after the full-breeding-plumage is assumed, is always the case in the Herring Gull, and also in both the Lesser and Greater Black-backs, thus distinguishing very old birds from those which, though adult, have only recently assumed the breeding-plumage. I know Mr. Howard Saunders is of this opinion, certainly as far as Herring Gulls are concerned. Besides the live ones, two skins I have, both of adult birds, as far as breeding-plumage only is concerned, are evidently considerably older than the other. No. 1, the youngest of these,--shot in Guernsey in August, when just assuming winter plumage, the head being much streaked, even then, with brown, showing that though adult it was not a very old bird,--has the usual white tip on the first primary, below which the whole feather is black on both webs, and below that a white spot on both webs, for an inch; the white, however, much encroached upon on the outer part of the outer web by a margin of black. In No. 2, probably the older bird, the first primary has the white tip and the white spot running into each other, thus making the tip of the feather for nearly two inches white, with only a slight patch of black on the outer web. On the second primary of No. 1 the white tip is present, but no white spot; but on the same feather of No. 2 there is a white spot on the inner web, about an inch from the white tip; this would, probably, in a still older