HOW ARCTIC ANIMALS TURN WHITE 63 
truth of Pennant’s statement, that the fact of the com- 
plete autumnal change of the coat in animals that turn 
white in winter was generally recognised by naturalists. 
So far as the spring change from the white to the brown 
dress is concerned, his conclusions are fully confirmed by 
Capt. G. E. H. Barrett-Hamilton, who communicated some 
interesting notes on the change in the European mountain 
or variable hare to the Proceedings of the Zoological Society 
of London for 1899. The fact that the vernal colour-change ; 
is due to the shedding of the coat seems, however, as : 
already mentioned, to have been much more generally 
admitted than was the case with regard to the autumnal 
transformation. 
Dr. Allen arrives at the conclusion that both the autumn ’ 
and the spring change take place periodically and quite 
independently of the will of the animal, and also that they 
are but little affected by phases of the weather, although 
they may be somewhat retarded or accelerated by the 
prevailing atmospheric temperature. 
So far as the fact of the seasonal change being normally 
beyond the control of the animal in which it occurs, Capt. 
Barrett-Hamilton is in full accord with the American writer ; 
but he goes somewhat further, and believes that it is quite 
uninfluenced by temperature, or at least by such variations 
of the same as may be met with in different parts of the 
area of the British Islands; and, as we all know, these are 
considerable ! 
As in the case of many other animals—deer, for instance 
—the change from the winter to the summer coat takes 
place very late in the season in the mountain hare in 
Scotland, specimens undergoing the change being often 
seen early in May. But the date of the spring change 
is no earlier in the south of Ireland, where the climate 
