BIRDS PERCHING BIRDS DIAGRAM 4. 71 



migrate in autumn, when their food begins to grow scarce. 

 Their nest is nothing but a convenient hole at the foot of a tree, 

 or in a rock, or even in the midst of paths in woods; and they 

 lay two eggs, marbled with bluish spots on a grey ground. 



The Swifts seem only to enjoy themselves in flight ; they have 

 very long wings, and such short legs, that they have the greatest 

 difficulty in walking. On the other hand, as their claws are very 

 sharp and slender, they cling easily to walls. 



The swift reaches this country in the spring, a little before the 

 swallows, and leaves a little sooner than the latter. It builds 

 its nest under the eaves or projecting roofs of houses, as well as 

 in cracks in walls and rocks, but when it finds the nest which it 

 built the year before, it does not take the trouble to build a new 

 one. It lines its nest with feathers which it has found floating 

 in the air, or which it picks up off the ground, and which it 

 sometimes steals from the nests of other birds, and especially 

 from the sparrows. Sometimes, too, the swift, instead of build- 

 ing a nest, is contented to repair that of another bird, which 

 it adapts for its use, and where the female lays three or four 

 white eggs. 



The Swallows. The beak of the swallow appears to be very 

 small, but is cleft to the eyes. They live on insects which they 

 catch flying, and assemble together in large flocks. 



About the beginning of April the swallows are seen to return 

 to the nests which they constructed in former years. On the 

 approach of winter, they assemble in multitudes on the roofs or 

 trees, and after a great fuss, accompanied with cries like the 

 tumult of a debate, they start off on their journey of some 

 hundreds or even thousands of miles. 



No bird appears to fly with so much ease as the swallows ; 

 they eat, drink, and sometimes even feed their young on the 

 wing. They are chiefly insectivorous, and consequently render 

 great service to agriculture. Their nests are generally built 

 against walls or buildings. They are cemented with earth in 

 the angles of walls, or eaves, with a small opening for the 



