BIRDS' NESTS 307 



the structure into a sort of hemispherical bowl 

 fastened to the wall and having a narrow mouth 

 at the top to allow the bird to squeeze through. 

 Bits of straw embedded in this masonry of earth 

 serve to give it greater solidity. Finally, the in- 

 side is upholstered with a quantity of fine feathers. 



"The chimney-swallow chooses a similar situation 

 for its nest and uses the same building-materials, 

 but the nest itself takes a differ- 

 ent form. Instead of a hemi- 

 spherical structure entered by a 

 very small opening, it builds a 

 cup-shaped nest, of no great 

 depth and wide-open at the top. 



' ' Swallows like to live together 

 in large numbers, so that their 

 nests are sometimes found touch- 

 ing one another in colonies of Nest of a swaiiow 

 several hundreds under the same cornice. Each 

 pair recognizes unerringly its own belongings and 

 respects scrupulously the property of others, in re- 

 turn for like respect paid to its own. There is 

 among them a deep sense of solidarity, and they 

 render mutual aid with no less intelligence than 

 zeal. 



"Sometimes it chances that a nest has hardly been 

 finished when it crumbles to pieces, the mortar used 

 having been of poor quality, or else the masons, 

 with injudicious haste, having had too little patience 

 to let one course dry before laying another on top 

 of it. At the news of this mishap neighbors of both 



