ANIMAL LIFE AND WINTER. 193 



in the soil are reduced, e.g. that of many insects, both in 

 the larval and the adult state ; of worms, snails, and slugs ; 

 of some fishes, e.g. chub, roach, mudfish ; to the well- 

 defined hibernation of frogs, toads, newts, snakes, lizards, 

 tortoises, hedgehogs, bats, dormouse, etc. 



While there is in general a correspondence between the 

 severe conditions of winter and hibernation, it will be well 

 to notice that the habit of hibernation is instinctive ; that 

 is, it is part of the inherited qualities in the animal 

 practising it, and has meaning with reference to the past 

 history of the type in the first instance. This will help to 

 explain how it is that bats, for example, may hibernate 

 quite early when food is plentiful and the weather is mild. 

 But in general it is probable that the actual cold is the 

 immediate inducing cause. In any case it is clearly of 

 value as a life-prolonging arrangement. 



(2) Some provide for winter by laying up stores in 

 autumn. Squirrels are our best illustration of this habit. 

 Pupils may sometimes have found their "hoards" at the 

 foot of trees. Hive bees also will be thought of. Arctic 

 foxes lay by stores, and some others, but on the whole 

 remarkably few creatures are endowed with the faculty of 

 providing for more than present needs. 



(3) Then there is the interesting case of those which flee 

 from winter, our migratory birds. Note in particular the 

 case of those birds which visit us in winter, e.g. fieldfare, 

 redwing, hooded crows, wood pigeons, etc. Also the resi- 

 dent birds which go from one region to another. Their 

 quest is the same as that of those who leave us at this 

 time, viz. easier conditions of climate and more abundant 

 food. 



(4) Notice next those who by structural adaptations are 

 fitted to meet the more rigorous conditions, those animals 

 which change colour, becoming white, There are three 

 such animals in G-reat Britain, the stoat or ermine, the 

 mountain hare, and the ptarmigan. The stoat is en- 

 abled to stalk its prey upon the snow with more likelihood 



N. S. 13 



