98 OUTLINES OF NATURAL HISTORY. 



bodies are protected against tlie cold by an ample cover- 

 ing of soft down. 



The Grey Lag or Grey-Legged Goose seems to be un- 

 questionably the parent of the domestic breeds of Geese. 



It was formerly very common in England, but is now 

 very rare. According to Gould, it " is known to inhabit 

 all the extensive marshy districts throughout the temperate 

 portions of Europe generally ; its range northwards not 

 extending further than the fifty-third degree of latitude, 

 while southwards it extends to the northern portions of 

 Africa, eastwardly to Persia, and, we believe, is generally 

 dispersed over Asia Minor." The Grey Lag Goose lives 

 upon grass, water-plants, and seeds, and abides mainly in 

 fens and marshy places. It not only swims and flies well, 

 but its walk, owing to the height of its legs, is not so 

 clumsy as is the case with many water-fowl. 



Recapitulation of Essential Characters. — The 

 animal is an air-breather, and at no time of its life pos- 

 sesses gills. The breathing-organs are in the form of lungs, 

 which communicate with air-receptacles, and (almost in- 

 variably) with the interior of a greater or less number of 

 the bones. The blood is hot, and the heart four-chambered. 

 The skull is jointed to the backbone by a single joint, 

 and the lower jaw is joined to the skull by means of a 

 " quadrate bone." The skin is provided with the peculiar 

 appendages which are known as feathers. The fore-limbs 

 (when not rudimentary) are organised for flight, and con- 

 stitute wings. The hind-limbs, in a state of nature, are 

 never provided with more than four toes. The mouth is 

 destitute of teeth, and the jaws are sheathed in horn. 

 The animal brings forth its young in the form of eggs. 

 These characters distinguish the class Aves as a whole. 



