WHEN THE SWALLOWS 
135 
generally early in flocking, but inclined to linger as 
long as food is abundant. Metallic blue-green above 
and pure white beneath, the white and colour meeting 
at a distinct line from the bill — this Swallow is 
readily distinguished and always admired. The Cliff 
Swallows are less familiar and seem to be decreasing 
in numbers. They have the mud-building habits 
and also the metallic blue-green plumage of the 
Barn Swallows. Reddish patches on the neck and 
above the tail are marks of identification. The big 
Black Swallow or Purple Martin is also becoming less 
common, and is said to show a growing inclination 
toward passing the summer in its southern home. 
The gathering of the flocks is a reminder of the passing 
of summer. Even in the oppressive and close evenings 
their chattering and crowding announce the distant 
approach of the frost king from the north. They will 
not wait for his blighting touch, but will seek the 
freedom of perpetual summer before the first chill of 
his approach. 
