on some birds concerning the continuation of whose song I seem at present to have some doubt. SELBORNE, June 30, 1769.

[As one of my neighbours was traversing Wolmer Forest from Bramshot, across the moors, he found a large uncommon bird fluttering in the heath, but not wounded, which he brought home alive. On examination it proved to be colymbus glacialis, Linn. the great speckled diver or loon, which is most excellently described in "Willughby's Ornithology."

Every part and proportion of this bird is so incomparably adapted to its mode of life, that in no instance do we see the wisdom of God in the creation to more advantage. The head is sharp and smaller than the part of the neck adjoining, in order that it may pierce the water; the wings are placed forward and out of the centre of gravity, for a purpose which shall be noticed hereafter; the thighs quite at the podex, in order to facilitate diving; and the legs are flat, and as sharp backwards almost as the edge of a knife, that in striking they may easily cut the water: while the feet are palmated, and broad for swimming, yet so folded up when advanced forward to take a fresh stroke, as to be full as narrow as the shank. The two exterior toes of the feet are longest; the nails flat and broad, resembling the human, which give strength and increase the power of swimming. The foot, when expanded, is not at right angles to the leg or body of the bird; but the exterior part inclining towards the head forms an acute angle with the body; the intention being not to give motion in the line of the legs themselves, but by the com

bined impulse of both in an intermediate line, the line of the body.

Most people know, that have observed at all, that the swimming of birds is nothing more than a walking in the water, where one foot succeeds the other as on the land; yet no one, as far as I am aware, has remarked that diving fowls, while under water, impel and row themselves forward by a motion of their wings, as well as by the impulse of their feet: but such is really the case, as any person may easily be convinced, who will observe ducks when hunted by dogs in a clear pond. Nor do I know that any one has given a reason why the wings of diving fowls are placed so forward: doubtless, not for the purpose of promoting their speed in flying, since that position certainly impedes it; but probably for the increase of their motion under water, by the use of four oars instead of two; yet were the wings and feet nearer together, as in land-birds, they would, when in action, rather hinder than assist one another.

This colymbus was of considerable bulk, weighing only three drachms short of three pounds avoirdupois. It measured in length from the bill to the tail (which was very short) two feet, and to the extremities of the toes four inches more; and the breadth of the wings expanded was 42 inches. A person attempted to eat the body, but found it very strong and rancid, as is the flesh of all birds living on fish. Divers or loons, though bred in the most northerly parts of Europe, yet are seen with us in very severe winters; and on the Thames are called sprat loons, because they prey much on that sort of fish.

The legs of the colymbi and mergi are placed so very backward, and so out of all centre of gravity,

that these birds cannot walk at all. They are called by Linnæus compedes, because they move on the ground as if shackled or fettered.

A man brought me a land-rail or daker-hen, a bird so rare in this district that we seldom see more than one or two in a season, and those only in autumn. This is deemed a bird of passage by all the writers: yet from its formation seems to be poorly qualified for migration; for its wings are short, and placed so forward, and out of the centre of gravity, that it flies in a very heavy and embarrassed manner, with its legs hanging down; and can hardly be sprung a second time, as it runs very fast, and seems to depend more on the swiftness of its feet than on its flying.

When we came to draw it, we found the entrails so soft and tender, that in appearance they might have been dressed like the ropes of a woodcock. The craw or crop was small and lank, containing a mucus; the gizzard thick and strong, and filled with small shell-snails, some whole, and many ground to pieces through the attrition which is occasioned by the muscular force and motion of that intestine. We saw no gravels among the food: perhaps 'the shellsnails might perform the functions of gravels or pebbles, and might grind one another. Land-rails used to abound formerly, I remember, in the low wet bean-fields of Christian Malford in North Wilts, and in the meadows near Paradise Gardens at Oxford, where I have often heard them cry 66 crex, crex.' The bird mentioned above weighed 74 oz., was fat and tender, and in flavour like the flesh of a woodcock. The liver was very large and delicate.]-OBSERVATIONS ON NATURE.

LETTER XXVI.

TO THOMAS PENNANT, ESQ.

T gives me satisfaction to find that my account of the ousel migration pleases you. You put a very shrewd question

when you ask me how I know that their autumnal migration is southward? Was not candour and openness the very life of natural history, I should pass over this query just as a sly commentator does over a crabbed passage in a classic; but common ingenuousness obliges me to confess, not without some degree of shame, that I only reasoned in that case from analogy. For as all other autumnal birds migrate from the northward to us, to partake of our milder winters, and return to the northward again when the rigorous cold abates, so I concluded that the ring-ousels did the same, as well as their congeners the fieldfares; and especially as ring-ousels are known to haunt cold mountainous countries: but I have good reason to suspect since that they may come to us from the westward; because I hear, from very good authority, that they breed on Dartmoor; and that they forsake that wild district about the time that our visitors appear, and do not return till late in the spring.

I have taken a great deal of pains about your salicaria and mine, with a white stroke over its eye, and a tawny rump. I have surveyed it alive and dead, and have procured several specimens; and am perfectly persuaded myself (and trust you will soon be convinced of the same) that it is neither more nor less than the passer arundinaceus minor of Ray. This bird, by some means or other, seems to be entirely omitted in the "British Zoology;" and one reason probably was, because it is so strangely classed in Ray, who ranges it among his pici affines. It ought no doubt to have gone among his small birds with the tail of one-colour (avicula caudá unicolore), and among your slender-billed birds of the same division. Linnæus might with great propriety have put it into his genus of motacilla, and the motacilla salicaria of his fauna suecica seems to come the nearest to it. It is no uncommon bird, haunting the sides of ponds and rivers where there is covert, and the reeds and sedges of moors. The country people in some places call it the sedge-bird.* It sings incessantly night and day during the breeding time, imitating the note of a sparrow, a swallow, a skylark; and has a strange hurrying manner in its song. My specimens correspond most minutely to the description of your fen-salicaria shot near Revesby. Mr. Ray has given an excellent characteristic of it when

* Salicaria phragmites, Selby, and Sylvia salicaria of Latham, here described, abounds in the midland counties, in moist hedge-rows, especially those choked up with reeds, hippuris, or horse-tails, and rushes. It reaches its summer quarters in April, and leaves in September. At first it is shy, and keeps close to the aquatic herbage which it affects. This shyness continues till May, when pairing takes place, and he becomes quite vociferous, a thorough mocking-bird, as described in the text.-ED.