PALMIPEDES. 



253 



Fig. 124. — Sternum uf Loon. 



pointed nails. Tliey are northern birds, which rarely nestle with us, and visit these latitudes in 

 winter, when they are not uncommon upon our coasts. [They have large wings, and fly strongly, 

 but in consequence of the position of the feet, the tibia being quite buried within the integuments, 

 are unable to walk, though they push themselves forward with facility and tolerable speed, trailing 

 upon the belly. They have a short tail, on the tripod of which and the feet they are enabled to 

 stand upright, and take a wide view around them by means of their long neck : they utter dismal 

 bowlings ; and produce large spotted eggs, two or three in number, which are extremely unlike those 

 of the Grebes. 



Three species are well known, the whole of which are not rare in Britain. One, as large as a Goose (Col. gla- 

 cialis), the Collared Loon, black above, beautifully spotted with white, with a nearly perfect collar of the same 

 round the neck, and a black head. The second, (C. glacialis), the Black-throated 

 Loon, extremely variable in size, but always smaller than the preceding-, with a fuli- 

 ginous grey head, and larger white spots on the upper parts : both of which species 

 have the immature plumage dusky above, with greyish edgings to the feathers : and 

 // ^ ] lkJ^_ / \ the Red-throated Loon (C. septentriumiUs), still smaller and much commoner, the 

 winter dress of which (and not the inmiature plumage, which resembles that of the 

 others, is speckled above with numerous small whitish spots bordering the feathers, 

 which wear otl" in spring, leaving the back spotless blackish ; coincident with which 

 change of appearance, a rufous patch appears in front of the neck. W\ three are 

 great destroyers offish, and proceed with extreme swiftness under water, in general 

 making little use of their wings to assist their progress. They are common to the 

 northern regions of both continents, as are also the four first-mentioned Grebes.] 



The Guillemots (Uria, Brisson & lUiger), — 

 With the general form of the beak of the preceding, have it covered with 

 feathers as far as the nostril, and emarginated at the tip, which is a little 

 arcuated. Their principal distinction, however, consists in wanting the 

 back-toe. Their wings, much shorter than those of the Loons, barely suflSce 

 for the function of flying. They feed on fish and crustaceans, and are found 

 about the precipitous rocks on which they breed. 



[These birds, the first of which is merely an Auk with a more slender bill, fly with considerable swiftness in a 

 straight line, their wings being reduced to the minimum extent adequate for aerial support, in order that they 

 might be more efficient under water, where no use whatever is made of the feet, 

 which are held out like those of a wading bird when cleaving the air. Ac- 

 cordingly they literally fly under water, whereas the subaquatic progression of a 

 Grebe more resembles that of a Frog, and the Loons do not generally use the 

 wings at all : hence the prolongation forward of the fixed patella, so considerable 

 in the Loons, which is reduced in the Grebes, and entirely wanting in the Auks, 

 Puffins, and Guillemots, which form a particular group, found only in the ocean. 

 The latter have also smaller coeca, a particularly tough cuticular lining to the 

 stomach, of a bright yellow colour, a different sternal apparatus, which most 

 nearly approximates that of the Loons, diverse plumage and seasonal changes, 

 &c. They are pre-eminently remarkable for the manner in which the skeleton 

 incloses the viscera as in a box, in order to resist the pressure of deep water; 

 while their air-cavities are unusually large, which causes them to float very high 

 when on the surface, and are obviously designed to increase the standard of 

 respiration so as to permit of their sustaining themselves in the air with their 

 short and narrow wings, the.se, however, not being violently beaten in the act of 

 flying. Their movements under water precisely resemble those of the XJ.v/icirftT, 

 or common Water Beetles ; the principal motion being more or less vertical, in- 

 stead of horizontal as in the Grebes and Loons: they are, therefore, together with 

 the distinct group of Penguins, the most characteristic divers of the class. 



One common on the precipitous coasts of all Britain, is the Common Guillemot 

 [U. troile), of a dusky slate-colour above, white beneath, and a bar of the same on 

 the wing, formed by the tips of the secondaries; the throat black in summer, ^' ^•— '""■""'" ""^"""''■"o'- 



white in winter. It lays only one egg, of enormous proportional magnitude, ana remarkably variable in colour. 

 The young at first resemble the adults in summer dress ; but their first plumage, which succeeds the down, and 

 the texture of which is singularly delicate, presents the colouring of the adult winter-garb, and is exchanged for 

 the latter in the course of a few weeks. Tliey breed in vast numbers on the narrow ledges of rocks, where in 

 many places they are seen sitting in successive rows, one over another. In autumn they migrate southward, 

 those which breed on the British shores being replaced by others from more northern latitudes. 



Another and smaller species, is the Black Guillemot {U. grylle), entirely black, with a great white wing-spot, in 



