PALMIPEDES. 



25.5 



Fi(f. 124.— Sternum cf Loon. 



pointed nails. They are northern birds, winch 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 

 hawlings; 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 

 the Red-throated Loon (C septentrionalti), still smaller and much commoner, the 

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

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

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

 change of appearance, a rufous patch appears in front of the neck. All 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 & Illiger), — 

 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 suffice 

 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 Frosr, 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 tou<rh 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 

 in. I i. arrow wings, these, however, not being violentlj beaten in the act of 



flying. Their movements under water precisel} resemble those of the Dyticid<e t 



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 cia^s. 

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



(f '. I mile), of a du^ky slate-colour above , white beneath, and a bar of the -a 



the wing, formed by the tips of the secondaries; the throat black in Bummer, 



white in wir.'er. It lays only one egg, of enormous proportional magnitude, ana remarkably variable in c dour. 

 The young at first resemble the adults in summer dress ; but then- first plumage, winch succeeds she down, and 

 the texture of which is singularl] delicate, presi ots the colouring of the adult winterrgarb, and is exchange d for 

 the latter in the com se of a feu weeks. 'I he> hie., i ni vast numbers on the narrow ledges of i "< ks, w here in 

 man} places the) are seen sitting in successive rows, one over another, in autumn thej migrate southward, 

 those winch breed on tin' British shores being replaced by others from mure northern latitudes. 

 Another and smallei Bpecies is the Black Guillemot (U. grylle), entire!} black, white wing-spot, in 



rttf. 125. — Sternum of Guillemot 



