328 ANATID^, 



quite 300 Swans about the bay and backwater ; and a good 

 many on the Exe (Zool, 1883, p. 452). A valuable account 

 of the Mute Swan on the rivers and broads of Norfolk has 

 been printed and privately distributed by Mr, H. Stevenson, 

 in anticipation of vol. iii. of his ' Birds of Norfolk.' 



The adult bird has the nail at the point of the beak, the 

 edge of the mandible on each side, the base, the lore, the 

 orifice of the nostrils and the tubercle, black ; the rest of the 

 beak reddish-orange ; the irides brown ; the head, neck, and 

 all the plumage pure white ; the legs, toes, and interdigital 

 membranes black. 



The whole length of an old male is from four feet eight 

 inches to five feet ; the weight about thirty pounds ; the black 

 tubercle at the base of the beak is larger than in the female ; 

 the neck is thicker, and the bird swims higher out of the 

 water. The body of the female is smaller, the neck more 

 slender, and she appears to swim deeper in the water. This 

 latter point is referable to a well-known anatomical law, that 

 females have less capacious lungs than males, and her body 

 therefore is less buoyant. Marked Swans have been known 

 to live fifty years. 



The young Mute Swan, in July, has plumage of a dark 

 bluish-grey, almost a sooty-grey ; the neck, and the under 

 surface of the body rather lighter in colour ; the beak lead- 

 colour ; the nostrils and the basal marginal line black. The 

 same birds, at the end of October, have the beak of a light 

 slate-grey, tinged with green ; the irides dark ; head, neck, 

 and all the upper surface of the body, nearly uniform sooty- 

 greyish brown ; the under surface also uniform, but of a 

 lighter shade of greyish -brown. Young birds at the end 

 of October are nearly as large as the old birds. After the 

 second autumn moult but little of the grey plumage remains ; 

 when two years old they are quite white ; and breed in their 

 third year. 



The figure here inserted represents the windpipe and 

 breast-bone of the Mute Swan. The keel is single, unpro- 

 vided with any cavity ; the windpipe descends between the 

 branches of the forked bone, and curving in the form of 



