GEOLOGY. 665 



tempered by the rains, and when he darts his vertical rays 

 upon the steppe the marshes are soon dried up, all the 

 plants wither and turn to dust, and a sea of ashes succeeds 

 to an ocean of verdure. The extreme heat stupefies the 

 crocodile and the boa-constrictor ; like the hibernating ani- 

 mals of the polar regions, they sink into the mud, and re- 

 main there motionless till the return of the rains. All the 

 animals express their sufferings by deep groans ; a few only 

 understand how to quench their thirst with the succulent 

 stems of certain Cacti, the spiny armor of which tears their 

 mouths and makes them bleed. 1 



When this consuming drought has wasted or burned up 

 the steppe, the torrid heat kills numbers of wild animals 

 which can find no place to slake their thirst, and their 

 corpses strew the ground in thousands. Night brings no 

 relief to such sufferings. Frightful bats attack the ex- 

 hausted animals, and, like the vampires of the old German 

 legends, suck their blood, only that they assail living flesh 

 and blood instead of betaking themselves to the corpses in 



1 " The mules," says Humboldt, " more circumspect, and wily, endeavor to 

 satisfy their thirst in another manner. A plant of spherical form, and bearing 

 numerous flutings, the Melocactus, contains a very watery pulp under a spiny en- 

 velope; the mule, by means of its fore-feet, separates the spines, puts down its 

 mouth carefully, and ventures to drink the refreshing juice. But it cannot always 

 drink at this living vegetable spring without danger. Animals are often seen 

 which have been lamed in the hoof by the spines of the cactus. 



" To tbe burning heat of day succeeds the freshness of the night, which equals 

 tbe day in duration; but the cattle and horses cannot even then enjoy repose. 

 During their sleep monstrous bats fasten like vampires on their backs, suck their 

 blood, and occasion purulent sores, in which horse-flies, mosquitoes, and a host 

 of other stinging insects establish themselves. Such is the painful life of these 

 animals so soon as ever the heat of the sun has made the water disappear frorn 

 the face of the earth." Humboldt, Tableaux de la Nature, b. i., s. 39. 



