192 OUT OF DOORS. 



hibernating animal and a tree in winter time. Indeed, 

 the latter is truly a living creature, though on a lower 

 plane than the lowest of the animals, and, as a partaker 

 of life, it accepts the two conditions of life nutriment 

 and respiration. Let the creature, whether plant or 

 animal, be able to exist for a time without the former 

 of these conditions or, rather, to exist for a time on 

 a store of nutriment already laid up and the latter 

 condition may be almost in abeyance. 



Take, for example, any of our hibernating animals, 

 from the mammal to the insect, and see how slight and 

 almost imperceptible is the respiration during the time 

 that nourishment ceases. We need not take into con- 

 sideration those insects which, in a perfect state, consume 

 no nourishment whatever, and yet act and respire 

 vigorously. Every one of them lives but a very short 

 life. They are burning away the stores of fuel already 

 laid up, and a few days at most are the utmost limit of 

 their existence. They have just sufficient vital power to 

 seek their mates and deposit their eggs, and straightway 

 die. But the plant has a comparatively long life before 

 it, and so has the hibernating animal ; and therefore 

 during the winter time there is vitality enough to 

 enable the creature to revive itself when the season of 

 spring comes round in its annual course. Specially is 

 this the case with the tree. Battered, withered, 

 pierced, torn, and half-eaten, the leaves of one year 

 could never act as efficient respiratory organs for the 

 increased needs of the tree in the ensuing season. So 



