NATURAL THEOLOGY. 321 



dison, " could not be followed with greater art or 

 diligence than is seen in hatching a chicken ; yet 

 is the process carried on without the least glim- 

 mering of thought or common sense. The hen 

 will mistake a piece of chalk for an egg — is in- 

 sensible of the increase or diminution of their num- 

 ber — does not distinguish between her own and 

 those of another species — is frightened ^vhen her 

 supposititious breed of ducklings take the water." 

 But it will be said, that what reason could not 

 do for the bird, observation, or instruction, or tra- 

 dition might. Now if it be true t hat a couple of 

 sparrows, brought up from the first in a state of 

 separation from all other birds, would build their 

 nest, and brood upon their eggs, then there is an 

 end of this solution. What can be the traditionary 

 knowledge of a chicken hatched in an oven ? 



Of young birds taken in their nests, a few spe- 

 cies breed when kept in cages ; and they which 

 do so build their nests nearly in the same manner 

 as in the wild state, and sit upon their eggs. This 

 is sufficient to prove an instinct without having 

 recourse to experiments upon birds hatched by 

 artificial heat, and deprived from their birth of all 

 communication with their species ; for we can 

 hardly bring ourselves to believe that the parent 

 bird informed her unfledged pupil of the history 

 of her gestation, her timely preparation of a nest, 

 her exclusion of the eggs, her long incubation, and 

 of the joyful eruption at last of her expected off- 

 spring : all which the bird in the cage must have 



