286 SWALLOWS AND MARTINS 



4. Nest and Eggs. The nest is placed at the end of a burrow, usually 

 two or three feet long, in the face of some steep bank, such as a railway cutting, 

 a river bank, gravel-pit, sand-pit, or natural bank of earth. Where suitable nesting 

 ground is available, many nests are placed in close proximity to one another, but 

 in default of proper nesting sites, the birds have been known to breed in holes 

 of stone walls or brickwork, large sawdust-heaps (Zool., 1876, 5108), in the gnarled 

 stem of an elm-tree (ZooL, 1870, 2344), or even in old nests of water-ouzel (Field, 

 May 30, 1892), and sandy ridges in an open meadow ( Victoria History of Cumber- 

 land, i. p. 8). The burrow slopes slightly upward, ending in a rounded chamber 

 where the nest is placed, a rude affair consisting of straw and rubbish with a pro- 

 fusion of feathers, and generally infested with parasites. (PI. xxx.) The work of boring 

 is shared by both sexes. Eggs usually 4 or 5, sometimes 6 or even 7 in number, 

 while in some districts 3 is rarely exceeded. They are dull white, without markings. 

 (PL D.) Average size of 100 eggs, -68 x -49 in. [17-3 x 12'5 mm.]. They are 

 generally laid from about the second week of May in the south and later in the 

 north, and incubation lasts about 12-13 days, according to Naumann. Accurate 

 and recent information on this point, and on the share of the parents in incubating, 

 is not at present available, and, on account of the position of the nest, is not easy 

 to obtain. Two broods are generally reared. [F. c. R. J.] 



5. Food. Insects, chiefly flies and small beetles. According to Naumann, 

 their favourite food consists of May-flies (Ephemera), gnats, and mosquitoes (Culex). 

 The young are fed by both parents. [F. B. K.] 



6. Song Period. The species sings more or less during the whole of its 

 stay. [F. B. K.] 



The following species are described in the supplementary chapter on "Rare 

 Birds":- 



Red-rumped Swallow, Chelidon rufula (Temminck). 

 American Purple Martin, Progne subis (Linnaeus). [F. c. R. J.] 



