14 LIFE ON THE EARTH. 



myrtles and laurels, the warm temperate zone of 

 evergreen trees, the cold temperate zone of deciduous 

 trees, the sub-arctic zone of pines, the arctic zone of 

 rhododendra, and finally, the polar zone where the 

 last relics of vegetable life expire 1 . 



The same succession of plants is found in ascend- 

 ing the lofty mountains of the equatorial zone, as 

 Chimborazo in South America, and Popocatepetl in 

 North America, whose summits have the polar climates, 

 and their slopes the plants and animals of different 

 latitudes. The ranges are equally definite on Etna, 

 but there the palm zone is only at the very base ; 

 and on Mont Blanc, which has none of the lower and 

 warmer zones. 



In a diagram, Fig. 1, the distribution in latitude 







of several races of mammalia is traced by lines. If we 

 regard the two halves of the circle divided by the 

 central meridian as representing the old and new 

 world, we shall find in each the same laws prevail 

 for the same groups ; though none of the species 

 are the same in the two regions, except toward the 

 north pole, where there is almost a connection of the 

 two countries by islands and ice. 



Thus the Platyrhine Monkeys of the new world 

 are balanced by the Catarhine Quadrumana of the 

 old world ; the Feline races of Asia and Africa, the 

 1 Humboldt. 



