THE CACTUS TRIBE. 21? 



with watery, and not unpleasantly flavoured acid juice. 

 This peculiarity gives them inestimable value to the fainting 

 traveller, and Bernardin de St. Pierre has aptly called 

 them the " Springs of the Desert." The wild Ass of the 

 Llanos, too, knows well how to avail himself of these 

 plants. In the dry season, when all animal life flees from 

 the glowing Pampas, when Cayman and Boa sink into 

 death-like sleep in the dried-up mud, the wild Ass alone, 

 traversing the steppe, knows how to guard against thirst ; 

 cautiously stripping off the dangerous spines of the Melo- 

 cactus with his hoof, and then in safety sucking the 

 cooling vegetable juice. In vertical extension, the Cacti 

 are not confined within such narrow limits, and they 

 stretch from the lowest tracts along the coast, through the 

 vast plains, up to the highest ridges of the Andes chain. 

 On the shore of the Lake Titicaca, 12,700 feet above the 

 level of the sea, are seen the tall-stemmed Peireskias with 

 their splendid deep brown-red blossoms, and on the 

 plateaux of southern Peru, near the limit of vegetation, 

 therefore about 14,000 feet high, the wanderer is surprised 

 by peculiar shapes of a yellowish-red colour, which at a 

 distance look like reposing savages, but which a closer 

 inspection reveals to be shapeless heaps of low Cacti, closely 

 beset with yellowish red spines. 



What Nature has withheld, however, in external aspect, 

 she has, in most, richly replaced in the magnificent 

 blossom. We are astonished to find the deformed grey- 

 green mass of the Mammillaria decked with the most 

 beautiful purple-red flowers. Strange is the contrast 

 between the wretched and gloomy aspect of the naked, 

 dry stem of the large-flowered Torch-thistle fCereus 

 grandiflorusj and its large, splendid, Isabel-coloured, 

 Vanilla-scented flowers, which, unfolding under cover of 



