5 o MOUNTAIN AND MOORLAND 



sink into a winter lethargy, and they are able to endure 

 a much lower body temperature than is possible for 

 Birds or Mammals. But if the outside temperature 

 falls below a certain limit in most cases an uncertain 

 limit they die. It is plain that these coldblooded 

 animals have not attained to that mastery of life which 

 we see in a Chamois, which seems to be quite com- 

 fortable on the Alps about the line of perpetual snow. 

 But all Mammals are not equally perfect in their 

 constitutional arrangements for "warmbloodedness." 

 This is very marked, for instance, in the three lowest 

 Mammals which lay eggs, the Duckmole and the two 

 Spiny Ant-eaters of Australia ; and the same imperfec- 

 tion is seen in some other cases. Now it seems clear 

 that hibernating Mammals are those which have cir- 

 cumvented this imperfection, and have made a 

 strength out of a weakness. The Bat and the Hedge- 

 hog, the Marmot and the Dormouse, are imperfectly 

 warmblooded just like nestling birds but they have 

 found a way out. When the winter approaches they 

 do not attempt the impossible, but sink into a state of 

 inactivity within a confined space, to the temperature 

 of which their body temperature tends to approxi- 

 mate. If they fell asleep in the open, they would 

 certainly be frozen to death; in a snug hole or shel- 

 tered nook the coma is more or less safe. But if the 

 sleeping-berth become very cold, and the sleeper does 

 not awaken in time, he passes from sleep into death. 

 Yet there is more than getting into a snug hole: 

 there is the practical cessation of activities. There is 

 rigid vital economy, just enough burning away of 

 stored fat and the like to compensate for the inevit- 

 able slight loss. What a strange state it is, with no 



