12 A necdotal Natural History. 



ing period they lie in a state of complete uncon- 

 sciousness, something more than sleep and less than 

 death, and which can be only partially described by 

 the word ' trance.' This state is not, as is generally 

 imagined, produced by intense cold ; lor should the 

 temperature fall below 32 Fahrenheit, or 'freezing- 

 point,' a hibernating animal is first awakened and 

 then killed by the frost. Those animals, therefore, 

 which pass the winter in a state of unconsciousness, 

 always select a retreat where they are sheltered from 

 the direct action of the elements, and where the 

 temperature is only slightly varied. 



While in the hibernating condition respiration en- 

 tirely ceases, and the animal could be kept for hours 

 under water, or in a vessel of carbonic acid gas, 

 without the slightest effect. The circulation of the 

 blood is greatly retarded, and digestion, at any rate 

 in those animals which spend the whole winter in 

 unconsciousness, is wholly at a standstill. 



The squirrel, however, is only a partial hibernator, 

 and is obliged to leave its hiding-place three or four 

 times during the winter months in search ol food. For 

 this purpose it always selects a milder day than usual, 

 and on such occasions may be seen repairing to its 

 stores for a meal before again proceeding to its place 

 of refuge. These hoards seem always to be more 

 than sufficient for its wants, and the remainder of the 

 provender is left to its fate. Sometimes the nuts, etc., 

 take root, and the squirrel is often the cause of trees 

 springing up in unexpected places. 



In the far north the cold of the winter has a very 

 marked effect upon the fur of these animals, which 

 from a rich brownish red becomes of a pale grey hue. 

 And even in our own climate there is a perceptible 

 change in the colour of the fur at different periods of 

 the year. 



