NATURAL CONDITIONS OF PLANTS. 5 
the heat rises to 170° or 180°, and the ground is 
occupied by cactuses, whose structure is such as 
to enable them to resist the extremest degree 
of drought. Were it not for such plants, these 
hot regions would form impassable barriers be- 
tween neighbouring countries. No water is to 
be found in these districts, nor anything to eat 
save the fruit of the Petaya, which Hardy tells 
us was the sole subsistence of himself and his 
party for four days. This, unlike other luscious 
fruit, rather allays than creates thirst, while, at 
the same time it satisfies, to a certain degree, 
the sensation of hunger. St. Pierre calls the 
cactuses, 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 flies from the glowing 
Pampas, when cayman and boa sink into death- 
like sleep in the dried-up mud ; the wild ass 
alone, traversing the steppes, knows how to 
quench his thirst, cautiously stripping off the 
dangerous spines of the melocactus with his 
hoof, and then, in safety, sucking the cooling 
vegetable juice. The Providence of God is 
equally manifested in cold countries, as in Lap- 
land — where the rein-deer moss furnishes the 
sole food, during winter, of the rein-deer, without 
which the inhabitants could not exist. 
