24 THE GEOGRAPHY OF PLANTS. 



springs ; some not far from the edge of the 

 Great Geyser, where every other plant is petri- 

 fied ; and species of confervce flourish in a 

 spring, said to be almost hot enough to boil an 

 egg. The influence of springs on the surround- 

 ing vegetation is also great, especially in the 

 tropics. In deserts, the smallest spring forms 

 in those climates an oasis, in which grasses, 

 juicy cyperi, and bushes grow, and even here 

 and there a palm rises. In the barren, sandy, 

 and parched-up deserts of the south of Peru, 

 between the Cordilleras and the coast, a spring, 

 however small, which rises often at wide in- 

 tervals, is the cause of a little settlement. 

 " Often it supports only a field of lucerne, a 

 little maize field, and a few olive trees ; and yet, 

 for the sake of this scanty produce, the great 

 roads must pass by such places, that the beasts 

 of burden may get the refreshment necessary 

 for them. Nothing can equal the dreariness 

 and death-like stillness in such regions of south 

 Peru. Sometimes, for twenty or thirty miles, 

 not a bird, not an insect, nor a plant is seen ; 

 but the smallest spring calls from this dead, 

 dusty soil, a green oasis ; and when rich mines 

 are near, is the source of great wealth, which 

 could not be obtained without it." 



Maritime plants are such as choose especially 

 for their localities places within the influence of 

 sea-air, or actually on the sea-coast. A beau- 

 tiful little plant, with deep green leaves, and 

 pretty little pink flowers, the saltwort, (Glaux 

 maritima,) abounds in damp, turfy spots, near 



