The Arctic Tern's Migration

The difference between night and day is dramatic - so dramatic that most species of animal can thrive either in the day or in the night but not both. They usually sleep during their 'off' period. Humans and most birds sleep by night and work at the business of living during the day. Hedgehogs and jaguars and many other mammals work by night and sleep by day. In the same way, animals have different ways f coping with the change between winter anc summer. Lots of mammals grow a thick, shaggy ...

 The Immensity of Time

How many times did the sun shine, how many times did the wind howl over the desolate tundras, over the bleak immensity of the Siberian taigas, over the brown deserts where the Earth's salt shines, over the high peaks capped with silver, over the shivering jungles, over the undulating forests of the tropics! Day after day, through infinite time, the scenery has changed in imperceptible features. Let us smile at the illusion of eternity that appears in these things, and while so many temporary ...