SONG BIRDS OF GREAT BRITAIN. 



dity of a stranger, it appears but seldom, and flies 

 but slowly and heavily along, frequenting lakes 

 and mill-ponds. As the weather grows warmer, and 

 its insect supply increases, it then gathers greater 

 strength and activity. Should severe weather pre- 

 vail, as it often does after its arrival, the Swallows 

 disappear, probably to collect in sheltered valleys, 

 where they sustain a bare existence on the few 

 insects they may find abroad till the return of 

 milder weather. When the weather promises to 

 be fair, the insect tribe feel the genial influence, 

 and make bolder flights : at that time the Swallow 

 follows them in their aerial journeys, and often 

 rises to imperceptible heights in the pursuit. When 

 the weather is likely to be foul, the insects feel the 

 first notices of it ; and from the Swallows follow- 

 ing low we are often apprised of the approaching 

 change. 



Swallows are distinguished from their congeners 

 as well by the length and forkedness of their tails, 

 as by the red spot on the forehead and under the 

 chin. They are the most nimble of all the spe- 

 cies ; and when the male pursues the female in 

 amorous chase, they then go beyond their usual 

 speed, and exert a rapidity almost too quick for 

 the eye to follow.* 



The food of this bird, as of the whole genus, is 

 winged insects ; in catching which it is extremely 

 dexterous ; and, considering the velocity of its 

 flight, its sight must be incomparably quick. 



The nest is made of mud plastered together, 



* White's Selborne. 



