46 LETTER XXX. 



more than the most scanty supply of necessary food. 

 Under such circumstances plants of an ordmary struc- 

 ture would perish ; but 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 sur- 

 rounds them is saturated vdth moisture, and the soil 

 they live in is drenched by ceaseless rains. At this 

 time they grow fast, all the little cavities in their 

 tissue, of which there are countless 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 

 scarcitv. But these supplies would be quickly con- 

 sumed by plants only protected by a thin cuticle, and 

 having their surface pierced by millions of breathing 

 pores, all actively exhaling the evaporable 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 surrounded it 

 during the season 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 the 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 



