THE EQUATORIAL ZONE. 285 



the height of 7000 and 8000 feet. Another splendid spe- 

 cies, which grows in a candelabra-like form, was found by 

 him "clothing the sides of the mountains in a singular 

 manner" on the Andes of Tacna and Arequipa, where 

 scarcely a trace of any other vegetation was to be seen ; 

 " only here and there rose one of these strange Cerei, the 

 stem of which divided, at the height of eight feet and up- 

 wards, into a number of branches from eight to twelve in 

 number which were round, and twisted in various directions, 

 sometimes upwards, sometimes downwards, or from side to 

 side." 



But the globular Cactuses, though not so showy, are 

 some of the most curious of the tribe. " They are often of 

 enormous size, with warts and thorns regularly distributed 

 over the surface," and are seated directly on the barren 

 ground or in the clefts of bare rocks. Their fleshy substance 

 possesses, in a most extraordinary degree, the property 

 which resides in all the tribe, of retaining a quantity of 

 watery sap from one rainy season to another ; so that when 

 everything else is dried up, they look " fresh and green, and 

 seem to thrive best in the most desert regions. They are 

 eagerly sought after and sucked by the wild asses and other 

 thirsty animals which roam over the dry deserts of South 



