220 The Cactus. 



more obvious connexion exists between the manner in wh' », 

 they are constructed, and the situations it is their destinv 

 live in. The greater number grow in hot, dry, rocky pl ace 

 where they are exposed for many months in the year to tk 

 fiercest beams of a tropical sun, without a possibility f i 

 taining from the parched and hardened soil, more than th 

 most scanty supply of necessary food. Under such circum 

 stances, plants of an ordinary structure would perish ; bm 

 Cactuses have a special power of resisting heat and drought, 

 and, like the Camel, they carry with them a supply of water 

 for many, not days, but months. It usually happens that once 

 a year, during several weeks at least, the air that surrounds 

 them is saturated with moisture, and the soil they live in j s 

 drenched by ceaseless rains. At this time they grow fW 

 all the little cavities in their tissue, of which there are count- 

 less millions, are filled with liquid nourishment, and they may 

 be literally said to gorge themselves with food. Then, when 

 the rains cease, and the air dries up, and the Spirit of the 

 desert reassumes his withering dominion over their climate 

 Cactuses are in the most robust health, and their cells are 

 abundantly filled with provision against scarcity. But these 

 supplies would be quickly consumed by plants only protected 

 by a thin epidermis, and having their surface pierced by 

 millions of breathing pores, all actively exhaling the evapor- 

 able matter that lies beneath them, and an early death would 

 be the inevitable result. Such, indeed, is the lot of all the gay 

 companions of the Cactus, which surround it during the sea- 

 son of feasting and prosperity, and to which Nature has given 

 no special means of enduring the hardships to which their lot 

 exposes them ; a few days or weeks suffice to sweep their 

 forms from the face of creation ; their leaves rapidly consume 

 the stores deposited in the stems ; their stems turn in vain to 

 the roots for a renewed supply, for after but a little while, the 

 arid earth has nothing to part with, and then the leaves wither 

 and fall off, the stems shrink up and crack with the dry heat, 

 and the roots themselves, in many cases, follow the same fate. 

 With Cactuses this is different ; they have so tough and thick 

 a hide, that what liquid substances they contain, can only pass 

 through it in minute quantities ; the breathing pores of their 



