ZOOLOGICAL GARDENS. 
11 
elongated necks and their short legs. There are, in all, 
ten species of swans, and in their distribution, with the 
exception mentioned above, they are confined to the tem¬ 
perate regions of the Northern and Southern Hemispheres. 
Ducks and geese, like swans, have four toes,three of which 
are turned forwards and webbed, while the fourth toe is direct¬ 
ed backwards. The true ducks, such as the pintail, widgeon 
and teal are distinguished from those ducks which chiefly 
frequent the sea, such as the golden-eye, pochard, canvas- 
back, &c., by their first toe being provided with only a 
narrow membranous lobe, whereas in the Scoters, Eiders 
and Mergansers this structure is very broad. The bill of 
ducks and geese is more or less spatulate and is a highly 
sensitive structure, as it is covered with skin richly supplied 
with nerves ; and in this respect it resembles the bill of 
the flamingo, and also in that the sides of the bill are pro¬ 
vided with a series of horny plates which act as a strainer. 
The well-known Indian duck, the Spotted-bill, Anas 
poecilorhyncha ) is represented here. This duck is peculiar 
to India, Ceylon and Burmah, being a permanent resident 
and not like the majority of ducks that occur in this coun¬ 
try, merely visitors during the cold weather months and 
leaving on the approach of the hot weather for the tem¬ 
perate regions to the north, crossing the Himalaya for 
their breeding grounds in Central Asia. 
Another non-migratory species generally to be seen in 
this tank, and essentially a bird of this country, is the 
Pink-headed duck, A. caryophyllacea , the males of which 
have the whole of the head and neck of a beautiful 
rosy pink, the rest of the body being dark-brown with a 
white spot appearing on the closed wing, the undersurface 
of which has a pinkish tint which becomes very observable 
