202 



ISLAND LIFE. 



[part I. 



proportions had been reversed, large areas of land would 

 necessarily have been removed from the beneficial influence of 

 aqueous currents or moisture-laden winds ; and slight geolo- 

 gical changes might easily lead to half the land surface becom- 

 ing covered with perpetual snow and ice, or being exposed 

 to extremes of summer heat and winter cold, of which our 

 water-permeated globe at present affords no example. We thus 

 see that what are usually regarded as geographical anomalies — 

 the disproportion of land and water, the gathering of the land 

 mainly into one hemisphere, and the singular arrangement of 

 the land in three great southward-pointing masses — are really 

 facts of the greatest significance and importance, since it is to 

 these very anomalies that the universal spread of vegetation 

 and the adaptability of so large a portion of the earth's surface 

 for human habitation is directly due. 



