200 CACTUS TRIBE. 



nient from the moisture of the atmosphere, and the 

 very little that is afforded by the earth from which 

 they spring. Saussure informs us that he once pre- 

 served the branch of a species of cactus for fourteen 

 months in a dark cupboard without either earth or 

 water, during which time the quicksilver fell nearly 

 seventeen degrees below the freezing point, while 

 in summer the heat was equal to seventy-eight de- 

 grees. The branch had not, when gathered from 

 its parent stem, been conveyed in full strength and 

 vigour to the place of destination ; it had previously 

 been subjected for at least three weeks to numerous 

 experiments, both in the sun and shade. At length 

 the cactus shrivelled up, and lost its juices, but 

 during the period of seclusion it threw out roots 

 and branches over its whole surface ; and not one 

 portion was deprived of its vegetative power. 



The cactus, in common with all succulent plants, 

 of which the unassuming houseleek offers a familiar 

 example, beautifully exemplifies that mighty power 

 which often causes regions naturally most unfavour- 

 able to vegetation to be covered with shrubs and 

 flowers. In countries parched with excessive heat, 

 and in places where few other plants would grow, 

 these plants often withstand the beams of a fervid 

 sun; they are provided for the purpose with large 

 vessels for absorbing moisture, and consequently 

 flourish on parched rocks, and in sandy deserts. 



The tribe of which the cactus is a member, is 

 curious and fantastic. Its numerous varieties rise 

 abruptly from out the ground; they have neither 

 leaves nor branches, and the stems are developed in 

 the most varied and eccentric manner. Yet the 



