66 . ORGANS OF BREATHING. 



We have alluded to the additional warmth pos- 

 sessed by birds, in comparison with other animals, to 

 which this greater quantity of air must essentially 

 conduce. We may here again refer to the Gannet, 

 which, passing so much of its time in the depth of 

 winter exposed to the severest weather, would, if 

 not provided with additional means of keeping itself 

 w T arm, often perish from cold; but having, as we have 

 observed, a power of filling up the space between its 

 flesh and outward skin with air, it is thus furnished 

 with a light, but at the same time admirable coat, 

 which effectually prevents it from feeling the effects 

 of cold, however severe. 



