HIBERNATION AND ALLIED STATES IN ANIMALS 83 
struggle for existence which has apparently been so 
great a factor in all kinds of development. 
On account of the destructive power of its teeth it 
became necessary to have a cage constructed of strong 
wire, with a suitable movable bottom, essential for 
cleanliness, 
My specimen would eat fruits, such roots as turnips 
and carrots, bread, biscuits, etc. But he became 
very fond of porridge with a little milk, and when 
he was disposing of this, his smacking could be 
heard all over the house. It seemed to agree with him 
perfectly. 
The object of my investigations being to ascertain 
not only the nature of the winter sleep, but the char- 
acter of its variations under a changing environment, 
especially as regards temperature and meteorological 
conditions generally, I kept the animal in different 
rooms of the houses in which I lived successively 
during the creature’s lifetime, and also in different 
parts of an outhouse in which my dogs, fowls, etc., 
lived. 
It would take up too much space and prove rather 
wearisome to attempt to reproduce here the records 
which I have kept in detail. It will be both more 
practicable and more profitable to give the general 
results of studies on this one specimen for the four 
years during which he lived, and then refer to the un- 
expected result of the study of another specimen during 
_ the past winter. 
I think the following life-periods were recognisable 
in the specimen I had under observation : 
(1) A period characterised by either drowsiness or 
sleep or profound torpor, lasting from about November 
to April. 
(2) A period of perfect wakefulness immediately 
following, during which the animal was emaciated, in 
