198 LIFE-HISTORIES OF BIRDS 



This species is devoid of a song; its only notes 

 being a few chirping calls which are easily recog- 

 nized. 



Nidification takes place generally about the 1 5th 

 of May, at least three or four days after mating; 

 and in cases where the excavation of a Bank 

 Swallow has been selected for the site of a nest, 

 it is but the work of a couple of days. Where the 

 birds are compelled tp excavate a place for them- 

 selves, they select a cliff composed of a soft, sandy 

 soil, which prolongs the period for two days more. 

 But where the crevices in the walls of a bridge are 

 chosen, for nidificating purposes, the structure 

 being necessarily more compact, it requires the 

 joint labor of the sexes for at least three days. The 

 nest like that of the Bank Swallow is constructed 

 of leaves and grasses, with a lining; of soft feathers. 



In 1843, in tne neighborhood of Carlisle, Prof. 

 Baird met a number of nests of this species, built 

 within crevices in walls, and the arches of bridges 

 over running water; in some instances being so 

 close to the edge of the water, as to suffer material 

 injuries in times of rain. Again, nests have been 

 observed in out-of-the-way-places, for example, 

 between the boards of a building in which was a 

 water-wheel, where the female had to pass through 

 a nut-hole to reach the nest. 



Oviposition immediately follows nest-completion, 

 an I continues for six days, one egg being de- 

 posited daily. Incubation ensues the succeedingday 

 and as far as we have been able to determine is 



