2

country where it no longer breeds,1 that incredulity as to its booming at all has in some quarters succeeded the old belief in this as in other reputed peculiarities of the species. The Bittern is found from Ireland to Japan, in India, and throughout the whole of Africa-suitable localities being, of course, understood. Australia and New Zealand have a kindred species, B. paciloptilus, and North America a third, B. mugitans or B. lentiginosus. The former is said to bellow like a bull, but authorities differ as to the vocal powers of the latter, which has several times wandered to Europe, and is distinguishable by its smaller size and uniform greyish-brown primaries, which want the tawny bars that characterize B. stellaris. Nine other species of Bitterns from various parts of the world are admitted by Schlegel (Mus. P.-B. Ardeæ, pp. 47-56), but some of them should perhaps be excluded from the genus Botaurus; on the other hand, Dr. Reichenow (Journ. f. Orn. 1877, pp. 241-251), by comprehending the birds of the Group Ardetta,-commonly known as "Little Bitterns," and differing a good deal from the true Bitterns-makes the whole number of species twenty-two.

BLACKBIRD, the common, but not the most ancient,3 name of the OUSEL, the Turdus merula,* of Linnæus and most ornithologists, one of the best known of British birds; but since conferred in distant countries on others whose only resemblance to the original bearer lies in their colour, as in North America to several members of the Icterida (GRACKLE and ICTERUS), in the West Indies to the species of Crotophaga (ANI), and perhaps to more in other lands. Occasionally too in translations of Scandinavian works it is used to render Svartfugl-the general name for the Alcide (AUK)—of which indeed it is an equivalent, but its use in that capacity tends to mistakes.

BLACKCAP, the Sylvia atricapilla of ornithology, one of the most delicate songsters of the British Islands, and fortunately of general distribution in summer. To quote the praise bestowed upon it in more than one passage by Gilbert White would be

1 The last recorded instance of the Bittern breeding in England was in 1868, as mentioned by Stevenson (Birds of Norfolk, ii. p. 164). All the true Bitterns, so far as is known, lay eggs of a light olive-brown colour.

2 Richardson, a most accurate observer, positively asserts (Fauna BorealiAmericana, ii. p. 374) that its booming exactly resembles that of its European congener, but few American ornithologists, Mr. Torrey (Auk, 1889, pp. 1-8) excepted, seem to have heard it in perfection.

3 Its earliest use seems to be in the Book of St. Albans in 1486, where it occurs as "blacke bride."

By some unhappy accident the order of these words is reversed in Dr. Murray's New English Dictionary. The bird has been named Merula atra, but never Merula turdus (as therein stated) by Linnæus or any one else.

superfluous. Enough to say that its tones always brought to his mind the lines in As You Like It (Act ii. sc. 5):

"And turn his merry note

Unto the sweet bird's throat."

The name, however, is only applicable to the cock bird of this species, who further differs from his browncapped mate by the pure ashygrey of his upper plumage; but notwithstanding the marked sexual difference in appearance, he shares with her the duty of incubation, and has been declared by more than one writer to sing while so employed a statement that seems hardly credible. Closely allied

to the Blackcap, which, it may be said, is a regular summer visitant, though examples have sometimes occurred in winter in England, are the so-called Garden-WARBLER, Sylvia salicaria (S. or Curruca hortensis of some authors), and the WHITE-THROAT.

But the name Blackcap is also applied to some other birds, and both in this country and in North America especially to certain species of TITMOUSE and GULL which have the top of the head black, as well as locally to the STONECHAT and Reed-BUNTING.

BLACKCOCK, the male of the bird to which the name Grows or GROUSE seems to have been originally given.

BLEATER, a name for the SNIPE, from the noise it makes in its love-flights, the cause of which has given rise to much discussion.

BLIGHT-BIRD, see Zosterops.

BLOOD is the fluid which circulates through the heart, arteries, and veins. It is mixed with lymph, its corpuscles being suspended in a fluid called blood-plasm. The arterial blood is of a lighter red than the venous, which is more purple blood. Blood shews the following composition:

1. Red blood-corpuscles, oval, flat disks, with rounded-off margins and a central nucleus which forms a slight swelling: they contain a substance known as hæmoglobin, which, combining with the oxygen of the blood, causes the latter's red colour. These red corpuscles are present even in a small drop of blood in innumerable numbers; they are largest in the Cassowary, smallest in Hummingbirds, their smallest axis measuring about mm. 110 or 1, their larger axis from mm. to

2. White-blood or lymph-corpuscles; by far less numerous, colourless, and of very variable size (from mm. 3 to 6), shewing lively amoeboid motions.

3. The blood-plasm, consisting of fibrin and serum. The latter is a fluid, frequently yellowish, and is composed of water, albumen, and various salts.

The function of the blood is this: The arterial blood in the capillaries of the body gives off its oxygen to the tissues of the body; the lymph, charged with the nutritive elements derived through the process of digestion, bathes the same tissues by leaving the capillaries, and is collected again into lymphatic vessels, being ultimately emptied into the big veins of the body, to be mixed again with the deoxydized blood returning likewise through the veins from the capillaries of the whole body. All this exhausted blood is, together with the lymph, received into the right auricle of the heart, thence pumped through the right ventricle and the pulmonary arteries into the capillaries of the lungs, there to give up its carbonic acid, and to be charged again with oxygen. Returning through the pulmonary veins into the left auricle, and thence into the left ventricle, it is forced by the contraction of the latter into the arteries of the body to commence its circulation

anew.

The lymph is a fluid like the blood-plasm, slightly yellowish or colourless and containing only white, but no red, bloodcorpuscles.

BLOOD-BIRD, one of the species of the genus Myzomela, belonging to the Meliphagida (HONEY-SUCKER), so called in New South Wales M. sanguinolenta (Latham). (Gould, Handb. B. Australia, i. p. 555.)

BLOOD-OLPH, a not uncommon local name of the BULL

FINCH.

BLOOD-PHEASANT, the Anglo-Indian name for the Ithaginis cruentus of ornithologists, one of the most beautiful game-birds of the mountains of Eastern Nepal and Sikkim, so called from the blood-red blotches with which its otherwise green plumage is diversified. A second species of the genus, I. geoffroyi, has been described from Northern China. By some systematists they are referred to the subfamily Perdicinæ, by others to the Phasianinæ. (Jerdon, B. India, iii. p. 522.)

BLUEBIRD, in North America the appropriate name of the no less familiar than favourite Sialia wilsoni, or sialis of ornithology, and of its congeners S. mexicana or occidentalis1 and S. arctica: the first, with a chestnut throat and breast, being an abundant bird on the eastern side of the continent, appearing also in Bermuda ; the second, with the middle of the back and breast chestnut, taking

1 By some writers S. mexicana is regarded as distinct from S. occidentalis, and there seems little doubt that S. azurea of Central America may be considered a good species. Mr. Seebohm (Cat. B. Brit. Mus. v. p. 328) places in this genus the Grandala cælicolor of the Himalaya and other mountain-ranges in Asia.

its place further to the south and westward; and the third, of a lighter hue and with no chestnut, being the north-western form. The genus Sialia is one of those that are midway between the reputed Families Sylviida (WARBLER) and Turdida (THRUSH), and with Monticola and some others shew how hard it is to maintain any valid distinction between them. The Bluebirds of North America breed in holes of trees, and seem all to lay pale blue spotless eggs. In Western India, Ceylon, and Burma, the name Bluebird is equally well bestowed on the Irena puella of modern ornithologists, which is commonly referred to the chaotic groups Timeliidæ or Crateropodida (Oates, Fauna of British India, Birds, i. pp. 239, 240), and has several representatives in the Indian Region (Jerdon, B. India, ii. p. 106); but the precise place of the genus must be regarded as uncertain. According to Mr. Layard (B. S. Afr. p. 365), in the seas of the Cape of Good Hope, the name is applied to a wholly different kind of bird, Diomedea fuliginosa (ALBATROS).

BLUECAP, a common name of the Blue TITMOUSE Parus

cæruleus.

BLUETHROAT, the English name by which the beautiful Motacilla suecica of Linnæus is now generally known. By some systematists it has been referred to the genus Ruticilla (REDSTART) or to Erithacus (REDBREAST), and by others regarded as the type of a distinct genus Cyanecula-the last view being perhaps justifiable. There are two, if not three, forms of Bluethroat in which the male is quite distinguishable (1) the true C. suecica, with a bright bay spot in the middle of its clear blue throat, breeding in Scandinavia, Northern Russia, and Siberia, and wintering in Abyssinia and India, though rarely appearing in the intermediate countries, to the wonder of all who have studied the mystery of the migration of birds; next there is (2) C. leucocyanea, with a white instead of a red gular spot, a more western form, ranging from Barbary to Germany and Holland; and lastly (3) C. wolfi, thought by some authorities (and not without reason) to be but an accidental variety of the preceding (2), with its throat wholly blue,-a form of comparatively rare occurrence. The first of these is a not unfrequent, though very irregular visitant to England, while the second has appeared there but seldom, and the third never, so far as is known. The affinity of the Bluethroat to the Redstart is undeniable; but it is not much further removed from the NIGHTINGALE, and forms a member of that group which connects the so-called Families Sylviida (WARBLER) and Turdidæ (THRUSH).

BOAT-BILL, the Cancroma cochlearia of most ornithologists, a native of Tropical America, and the only species of its genus. It seems to be merely a Night-HERON (Nycticorax) with an exaggerated bill, so much widened as to suggest its English name, and its habits,

so far as they are known, confirm the inference derived from its The wonderful "Shoe-bird" or Whale-headed STORK

structure.

(Balaniceps) is regarded by some authorities as allied to Cancroma; but the present writer cannot recognize in it any close affinity to the Ardeida.

BOATSWAIN, in seamen's ornithology, is a name applied to several kinds of birds, and was perhaps first given to some of the genus Stercorarius (SKUA), though nowadays most commonly used for the species of Phaethon (TROPIC-BIRD), the projecting middle feathers of the tail in each being generally likened to the marlinespike that is identified with the business of that functionary, but probably the authoritative character assumed by both Skua and officer originally suggested the appellation.

BOAT-TAIL, a common name applied to certain North-American birds of the genus Quiscalus, belonging to the Family Icterida (see GRACKLE and ICTERUS), from the power they have of holding the tail in the shape of a boat with the concavity uppermost.

BOB-LINCOLN, BOBLINK, and BOBOLINK, names given by the English in North America to what is commonly called in books the Rice-Bunting, Dolichonyx oryzivora, one of the best-known birds of that continent-valued for its song and still more for its sapidity, in which last respect it equals if it does not surpass the famed