366 THE STOAT. 
The change of colour which takes place during the colder months of the year is now 
ascertained, with tolerable accurac y, to be caused by an actual whitening of the fur, and 
not by the gradual substitution of ‘white for dark hairs, as was for some time supposed to 
be the case. 
The hairs are not entirely white, even in their most completely blanched state, but 
partake of a very delicate cream-yellow, especially upon the under portions, while the 
shehtly bushy tip of the tail remains in its original black tinting, and presents a singular 
contrast to the remainder of the fur. In these comparatively temperate latitudes, the 
Stoat is never sufficiently blanched to render its fur of any commercial value, and the 
hair appears to be longer, thicker, and whiter in proportion to the degree of latitude in 
which the animal has been taken, As may be supposed, from the extreme delicacy of the 
skin in its wintry whiteness, the capture of the Stoat for the purpose of obtaining its fur 
isa matter of no small difficulty. The traps which are used for the purpose of destroying 
the Stoat are formed so as to kill the animal by a sudden blow, without wounding the 
skin; and many of the beautiful little creatures are taken in ordinary snares. 
The object of the whitened fur of the Stoat is popularly supposed to be for the purpose 
of enabling the animal to elude its enemies by its similarity to the snow-covered eround 
on which it walks, or to permit it to creep unseen upon its prey. It seems, however, that 
many animals partake of the same tinting, some of which, such as the polar bear, are so 
powerful, that they need no such defence against enemies, and so active in the pursuit of 
the animals on which they feed, that their suecess in obtaiming food seems to depend but 
little upon colour. The arctic fox, which has already been mentioned on page 336, and the 
lemming, which will be recorded in a future page, are examples of this curious mutation 
of colour 
Putting aside for the present the mode in which the fur changes its colour, the real 
object of the change appears to be for the purpose of defending the wearer against the 
intense colds which reign in those northern regions, and which, by a beautiful provision, 
ave obliged to work the very change of colour which is the best defence against their 
powers. It is well known that black substances radiate heat more effectually than objects 
which are bright and polished. This fact is popularly shown in the bright teapots with 
which we are so familiar, and which are known, by practical experience, to retain the heat 
for a much longer period than if their surface had been roughened or blackened. 
The reader will not fail to remark a certain coincidence between the snowy hairs that 
deck the frosty brows of old age with a reverend crown and the white fur that adds such 
beauty to the frost-beset Stoat. It may be that the energies of the animal are forced, by 
the necessity which exists for resisting the extremely low te mperature of those icy regions, 
to concentrate themselves upon the vital organs, and ave unable to spare a suffici lency 
of blood to form the colouring matter that tinges the hair. There is evidently an analogy 
between the chilly feeling that always accompanies old age and the frosty climate that 
causes the Stoat’s fur to whiten. 
It is well known that examples of albinos occur in almost every kind of quadruped 
and bird, and it seems probable that the deprivation of colour is in very many cases owing 
to the weak constitution of the individual. One of these albinos was a bird, which was 
caueht and tamed, and ee! it was of a cream colour when it was captured, va 
assumed the usual dark plumage of the species at the first moulting season that 
occurred after its capture. As the bird also appeared to be much more hee uthy and lively 
than when it was clad in white feathers, it seems likely that the albino sti a may have 
been caused by weakness of constitution. 
It is clear that, whatever may be the immediate cause of the whitening of the hair, 
the change of tint is caused by the loss of the colouring matter which tinges the hair, and 
that there must be some connexion between the frost-whitened Stoat, the age-whitened 
human hair, and the abnormal whiteness of various albinos. I would also mention, in 
connexion with this subject, the curious instances where the hair of human beings has 
been suddenly blanched by powerful es This fact has been disputed by several 
physiologists, but is now acknowle¢ leed to be true. Besides the various well-attested 
examples which are on record, I am enabled to eive my own personal testimony to the 
are 
