Vei'min of the Farm. 473 
place either in the weasel or in the polecat, both members of 
the same family. 
Bell, in his British Quadrupeds (2nd ed.,p. 196), states that 
“ this is effected not by the loss of the summer coat and the 
.substitution of a new one for the winter, but by the actual 
change of colour in the existing fur,” On the other hand, the 
late Henry Wheelwright, better known as a writer on natural 
history under the signature of “ The Old Bushman,” has asserted 
just the reverse, stating that he had proved it by keeping 
specimens in confinement.* 
There are other statements by Bell which are likewise open 
Fig. 7. — Tlie Stoat, Mustela erminea. 
to criticism, as for example his remark (op. cif. p. 196) that the 
change to white “arises from a similar cause to that which 
produces the grey hair of senility in man.” But in man, after 
the change to grey or white, the normal colour is never resumed, 
while in the stoat it is otherwise. Again, he observes that 
“ the access of very sudden and severe cold has been known to 
produce the winter change.” But even in the south of England 
stoats have been found to have undergone a partial change to 
white long before the advent of winter. In 1887 we received 
' Ten Years in Sweden, p. 219. This was also the opinion of the late 
Edward Blyth, one of the most experienced zoologists of modern times. 
