268 NATURAL HISTORY 



on it as its own, to eject the owner, and to 

 line it after its own manner. 



After so much labour is bestowed in 

 erecting a mansion, as Nature seldom works 

 in vain, martins Avill breed on for several 

 years together in the same nest, where it 

 happens to be well sheltered and secure 

 from the injuries of weather. The shell or 

 crust of the nest is a sort of rustic- work full 

 of knobs and protuberances on the outside : 

 nor is the inside of those that I have exa- 

 mined smoothed with any exactness at all ; 

 but is rendered soft and warm, and fit for 

 incubation, by a lining of small straws, 

 grasses, and feathers ; and sometimes by a 

 bed of moss interwoven with wool. In this 

 nest they tread, or engender, frequently 

 during the time of building ; and the hen 

 lays from three to five white eggs. 



At first when the young are hatched, and 

 are in a naked and helpless condition, the 

 parent birds, M^th tender assiduity, carry 

 out what comes away from their young. 

 Was it not for this affectionate cleanliness 

 the nestlings would soon be burnt up, and 



