TWO FASHIONABLE FURS 209 
together, but that the blue variety was very rare.” Again, 
in answer to inquiries on this subject, Dr. Einar Lonnberg, 
of Upsala, whose observations are based on personal ex- 
perience, wrote to me as follows :— 
“The ‘blue’ foxes are uniformly dark-coloured summer 
and winter, and do not change to white at any time. In 
the summer they are very dark—dark brown, in fact; in 
winter they are also dark, but more bluish. The indi- 
viduals which turn white in winter are during the summer 
ashy grey on the upper-parts and limbs, but have the tail, 
under-parts, more or less of the flanks, and the ears and 
muzzle white. The distribution of the grey and white is, 
however, subject to individual variation. The ‘blue’ fox 
is, in fact, merely an individual variety of the white one. 
Both breed together, and sometimes there are dark and 
light individuals in the same litter. A friend of mine 
observed on Bear Island a pair in which the female was 
white and the male blue. In Iceland it is stated that all 
the Arctic foxes are blue.” 
More precise information is required on the subject of 
their interbreeding, but it is quite certain that the blue fox 
and white fox of the furrier are only individual phases of 
the winter coat of a single species of fox. 
Although it is stated that white specimens are occa- 
sionally met with in summer, the white phase of the Arctic 
fox (as the species is called) normally assumes a dark 
coat in summer. The difference between the winter and 
summer coats of this phase of the species is well illustrated 
by a couple of specimens which have recently been placed 
in the central hall of the Natural History branch of the 
British Museum. In the case containing the mountain- 
hare, ptarmigan, stoat, and weasel in their white winter 
dress has been introduced a specimen of the Arctic fox in 
14 
