Page:The Zoologist, 4th series, vol 5 (1901).djvu/210

186 questions of age and sex may be disregarded, as the sexes are the same size, and, once the young are able to fly, their bills and wings appear to reach their normal adult development. As will be seen on reference to the list of measurements, almost all the specimens were obtained in two localities a few miles apart, namely, between Dungeness and Littlestone in Kent, and at Rye Harbour in Sussex. At Littlestone there are no drains, and the shore is merely a flat stretch of sand and shingle; while at Rye there is a large extent of shore, a river with high banks uncovered at low water, and a small sailing intersected by drains. Of the ten birds from Littlestone, only one is of the small form; and of twelve specimens from Rye, half of them belong to the short-billed race—a result which certainly tends to confirm Mr. Backhouse's remarks. It is unfortunately not noted which of the Rye birds were shot on the shore, and which in the drains, or possibly the results might be of a still more confirmatory character. Of two birds, however, shot on the fjeld near Vadsö, in Norwegian Lapland, one belongs to the large race and one to the small, and these birds were at that time breeding near the same place, and in a precisely similar situation, viz. a wet swamp on the fjeld some two miles from the coast. Mr. Barrington, in his recent work on the Migration of Irish Birds, gives the measurements of the wings of twenty-four examples, showing all variations from 4·87 in. to 3·95 in., neither form preponderating at any particular station. If these forms were in reality distinct races, we should expect to find either (1) that there was a distinct break in the continuity of the measurements, or (2) that their geographical distribution was different—at any rate, during some period of the year. But, as neither of these tests is borne out by the facts, and wherever the species is found both forms occur in fairly equal numbers, they can only be considered as the extremes of a very variable species. It is at the same time interesting to note that the difference in length of the bill is to a certain extent correlated with different habits, and, if one may be permitted to theorise, it seems probable that in this case the bill has influenced the habits, and not vice versâ, as is generally the case.