HOUSE MAKTIN. 317 



cerifera, a shrub belonging to the same genus as the well-known 

 British shrub called Sweet Gale, or Dutch Myrtle. 



Another American bird, the Ex^'OUS-bellied Swallow (ITirMmZo 

 erythrogaster), is notable for the nest which it makes. This species 

 follows the example of the Oven Bird in its selection of materials, 

 strengthening the mud walls of its nest with fine hay. The nest 

 is furthermore remarkable for having a supplementary perch, or 

 small nest attached to the larger one, serving as a seat for the 

 male, •whUe his mate is engaged in the business of incubation. 

 On such occasions he is in the habit of pouring forth a lively, 

 though not varied song, being, in fact, a sustained twitter. The 

 shell of the nest is about an inch in thickness, and the mixed 

 mud and hay are arranged in regular layers. Owing to the 

 thickness, and the complicated structure of the nest, a full week 

 is required for its completion. The form of the nest is nearly 

 that of an inverted cone, being flattened on the side which is set 

 against the wall or rock. The bird is of gregarious habits, and 

 twenty or thirty nests are often seen so close together that a 

 finger can scarcely be placed between them. 



Fortunately for itself, this bird is protected by popular super- 

 stition, which attributes aU kinds of ill-luck to the person who 

 kills one of them. Wilson remarks that, in consequence of long 

 immunity, they feel so secure among human habitations, that 

 although the woods may be destitute of them, every farm-house 

 is sure to attract them. There is scarcely a bam in which they 

 will not build; and right glad is the farmer when they take 

 possession of a house, for, according to popular belief, such a 

 building wiU never be injured by lightning. He further men- 

 tions, that a farmer said, that if he were to permit his swallows 

 to be shot, all his cows would give bloody milk; to which remark 

 Wilson merely nodded assent, being unwilling to disturb any 

 feeling, however superstitious, which had for its object the 

 protection of useful birds. 



We have several builders among our British birds, the best 

 known of which is the common Hotjse Maetin {Chelidon urbica), 

 whose nests are so plentiful upon the walls of our houses. 



The material of which the nests are built is a kind of mud, 

 which becomes tolerably hard when dry, and is strong enough 



