THE SEASON OF THE YEAR. 



2 35 



glaciers of mountain systems. And here we come face to face with 

 the very core of our problem: for the odd part of it is that seasons 

 (at least as we know them) seem to be quite a recent and exceptional 

 phenomenon in the history of our planet. So far as we can judge, 

 geologically speaking, the earth during all its earlier life enjoyed, 

 over all its surface, what we should now consider tropical or sub- 

 tropical conditions. England — or rather the land that occupied the 

 part of the earth's crust where England now stands — had a vegeta- 

 tion of huge tree ferns and palms and cycads during the Primary 

 period; as late even as the middle Tertiaries it had a vegetation like 

 that of South Carolina or Upper India. Greenland itself, in quite 

 recent times, nourished like a green bay tree, and did not belie its 

 odd modern name. The world as a whole enjoyed perpetual summer: 

 In one word, except in something like the equatorial sense, there 

 were practically no seasons. The sun went north and south, no 

 doubt, as now, but the temperature, even in the relative winter, 

 seems to have remained perennially mild and genial. 



It is true, occasional slight traces of glacial epochs, earlier than 

 the great and well-known Glacial epoch, break here and there the 

 almost continuous geological record of palmy and balmy world-wide 

 summers; yet, taking the geological monuments as a whole, they 

 show us few or no signs of anything worth calling a serious winter 

 till quite recent periods. Large-leaved evergreens are still, in the 

 day -bef ore-yesterday of geology, the order of the day ; magnolias and 

 liquidambars, cinnamons and holly oaks, vines and rotang palms 

 formed the forests even of Miocene Britain. The animals during 

 all the Tertiary period were of what we now regard as tropical or 

 subtropical types — lions, rhinoceroses, hippopotamuses, monkeys, or 

 more antique races, equally southern in aspect. There could have 

 been little change of winter and summer during this long warm 

 spell; the variations can have been scarcely more than those of dry 

 and rainy seasons. The trees never lost their leaves; the fruits and 

 flowers never ceased to follow one another; no interruption of the 

 food supply drove insects to hibernate in their silken cocoons, or 

 squirrels and bears to lay by stores of food or fat for the cold and 

 hungry winter. 



Nevertheless, taking the world round as it stands, we must be- 

 lieve that the distinction of seasons grew up, both for plants and 

 animals, and for man or his ancestors, during this age of relatively 

 unmarked summers and winters. For the tropics more than any- 

 where else preserve for us to-day the general features and aspect of 

 this earlier time; they have never had the continuity of their stream 

 of life rudely interrupted by the enormous changes of the Glacial 

 epoch. Yet, even in the tropics, things, as we saw, have seasons. 



