216 A SKETCH OF 



they are all distinguished by an extraordinarily fleshy stem, 

 which, clothed by a greyish-green, leathery cuticle, and 

 beset, in the places where leaves are situated in regular 

 plants, with various tufts of hairs, spines and points, gives 

 by its very varied degrees of development, the varied 

 character of the plants. The Torch-thistles rise in form 

 of nine-angled or often round columns, to a height of 

 thirty or forty feet, mostly branchless, but sometimes rami- 

 fying in the strangest ways, and looking like candelabra ; 

 the Indian Figs are more humble ; their oval, flat branches, 

 arranged upon one another on all sides, produce special 

 forms. The lowest and thickest Torch-thistles connect 

 themselves with Hedgehog and Melon-Cactuses, with their 

 projecting ribs, and thus lead us to the almost perfectly 

 globular Mammillarias, which are covered very regularly 

 with fleshy warts of various heights. Finally, there are 

 forms in which the growth in the longitudinal direction 

 prevails, which with long, thin, often whip-like stems, like 

 that of the Serpent-Cactus, so often cultivated here, 

 hang down from the trees upon which they live as 

 parasites.* 



Few families have so limited a range of distribution upon 

 the globe. All the species of Cactus, perhaps without a 

 single exception, are indigenous in America, between the 

 parallels of 40 S. lat and 40 N. lat. But some of them 

 were so rapidly distributed through the Old World directly 

 after the discovery of America, that they may almost be 

 looked upon as fully naturalized there. Almost all delight 

 in a dry situation, exposed to the burning rays of the sun, 

 which contrasts strangely with their fleshy tissue, tumid 



* See the Vignette, in which the principal forms of this group of 

 plants are represented. 



