ORGANS OF BREATHING. 
55 
would, if not provided with, additional means of keeping itself 
warm, often perish from cold; hut 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, hut 
at the same time admirable coat, which effectually prevents 
it from feeling the effects of cold, however severe. 
