TWO DAYS WITH THE TERNS 115 
the wing, and the series of pictures shown represents 
the stages of growth from the egg to the age at 
which the bird takes flight. 
Both the nature of the bird’s haunts and the 
manner in which the members of a colony spread an 
alarm make it practically impossible to surprise a 
Tern upon its nest. But by lying prone upon the 
ground one attracts far less attention than when 
standing. The hovering flock of birds gradually 
disperses, and those which are incubating soon re- 
turn to the vicinity of their nests, hanging over 
them and dropping nearer and nearer,** until at the 
end of fifteen or twenty minutes they swoop down 
beside them, raise their wings high over their backs, 
then fold them gently and settle upon their eggs.® 
On a second visit to the island a bit of old sail 
was brought, which I drew over me when lying on 
the ground—a plan resulting in my practical disap- 
pearance, as far as the Terns were concerned, 
