EXCURSIONS OF AN EVOLUTIONIST 



in midsummer, even while oranges and palms 

 are flourishing a few thousand feet below. It is 

 not quite so familiar a fact that no intensity of 

 arctic cold will suffice to prevent a warm or mild 

 summer unless there is an extensive deposit of 

 snow in the winter. Now, nowhere on the earth 

 do we find any lowlands of great extent covered 

 with perpetual snow. The coldest winters on the 

 globe occur in eastern Siberia, where the temper- 

 ature often averages 40 F. for several weeks 

 in succession, and, according to Professor Pum- 

 pelly, sometimes sinks to 120 F. ! Yet so 

 dry is the atmosphere that but little snow falls, 

 and after this has been melted in the spring the 

 weather rapidly grows warm. " At Yakutsk, in 

 62 degrees N. latitude, the thermometer stands 

 often at 77 in the shade, and wheat and rye pro- 

 duce from fifteen to forty fold," while the prairies 

 are covered with grass and flowers. As Mr. Wal- 

 lace observes, " it is only where there are lofty 

 mountains or plateaus as in Greenland, Spitz- 

 bergen, and Grinnell Land that glaciers, ac- 

 companied by perpetual snow, cover the country, 

 and descend in places to the level of the sea." 

 The coast of the Antarctic Continent is girded 

 with lofty mountains, which effect such conden- 

 sation in the damp sea-air about them that the 

 continent is buried under a mass of ice more than 

 a mile in thickness. The antarctic islands South 

 Georgia and South Shetland " are very moun- 

 62 



