THE STOAT, OR ERMINE. 101 



" One object of this change of colour, is the safety the 

 animal obtains by an approximation in its colour to that of 

 the earth's winter covering. The alpine hare, the ptarmigan, 

 and many other mammals and birds, are more or less liable 

 to become the prey of rapacious birds or other creatures, 

 which are directed in the chace by their sight. The mottled 

 browns which form the principal summer colours of these crea- 

 tures, are well adapted for their concealment amongst the 

 brown heaths and fern of the summer and autumn -, but such 

 colours would render them conspicuous by contrast among 

 the snows of winter. 



" But this, though perhaps the most obvious, is not the most 

 important advantage gained by the assumption of the white 

 clothing in the winter season. It is well known that although 

 the darker colours absorb heat to a greater degree than lighter 

 ones, so that a dark is much warmer than a light-coloured 

 clothing, when the wearer is exposed to the sun's rays the 

 radiation of heat is also much greater from a dark than from 

 a light- coloured surface, and consequently the animal heat from 

 within is more completely retained by a white than by a dark 

 covering : the temperature therefore of an animal having white 

 fur, would continue more equable than that of one clothed in 

 darker colours, although the latter would enjoy a greater degree 

 of warmth while exposed to the sun's influence. Thus the 

 mere presence of a degree of cold, sufficient to prove hurtful if 

 not fatal to the animal, is itself the immediate cause of such a 

 change in its condition, as shall at once negative its injurious 

 influence."* 



The stoat haunts woods, hedges, and meadows 5 especially 

 where there are brooks, whose sides are covered with small 

 bushes j and sometimes, though not so often as the weasel, it 

 inhabits barns and other buildings. In Siberia it burrows in 

 the fields ; and in Britain it is known often to lodge during the 

 winter in the excavations of the mole. 



It pursues its prey by tracing the scent, exactly in the manner 

 * Abridged from A History of British Quadrupeds (1837), p. 150154. 



