84 
STERNID^. 
from ten to a dozen pair breed in company, depositing their 
two or three eggs on the bare ground, without forming 
any nest whatever. The female sits all night on the eggs, 
and the male takes her place from time to time during 
the day, if the weather requires them to be kept warm, while 
the female feeds ; or the eggs are left to be warmed by the 
rays of the sun ; in sixteen days the young come forth, and 
in three weeks more they are sufficiently fledged to fol¬ 
low their parents on the wing. 
The Common Tern measures fifteen inches in entire 
length ; the beak, fifteen lines from the forehead, and twenty- 
two lines from the gape to the tip ; the tarsi, nine lines ; 
the wing, ten inches from the carpus to the tip ; the outer 
feathers of the tail, five inches three lines ; the middle feathers, 
three inches nine lines, which shows the exact fork of the 
tail. 
The plumage of the young male in the autumn is as 
follows : the forehead and top of the head, hoary^black ; 
the nape and hinder part of the head and ear-coverts, ex¬ 
tending over the eye, and just before the eye, are black, 
as well as the hinder part of the neck, as represented in 
our plate; the back, scapulars, wing-coverts, and outer 
webs of the tail-feathers, with exception of the two middle 
ones, are gull grey. The feathers of the back and lesser 
wing-coverts are marked with ferruginous crescent-shaped 
stains ; the secondaries and tertials are tipped with white ; 
the quills are grey, their tips hoary grey, and the outer web 
of the first, black ; the spurious wing, white ; the chin, sides 
of the face, and all the under parts, rump, and tail-coverts, 
white; the beak is salmon-coloured, the upper ridge and 
tip, dusky ; legs and feet, salmon-colour ; the claws, dusky ; 
the eyes, dusky brown. 
The spring plumage of the adult has the upper part of the 
