136 THE GEOGRAPHY OF PLANTS. 



our hot-houses, reaches a considerable size, is 

 said to attain a circumference of three hundred 

 or four hundred feet at the Cape, and yet the 

 soil is nowhere drier than in those places 

 where the aloes are found. Great succulent 

 prickly euphorbias also abound here, some of 

 which grow into trees forty feet high. 



Plants of the genera Cycas and Zamia are 

 found frequenting the West Indies, Japan, 

 and Madagascar. They most resemble palms, 

 with very short stems, though one which 

 grows on the west coast of Australia is thirty 

 feet high. Some of these yield a kind of 

 arrow-root and sago ; the sago produced from 

 Cycas revoluta is said to be held in the highest 

 esteem ; soldiers are able to exist for a long 

 time on a very small quantity of it, and the 

 laws of Japan forbid the removal of the plants 

 from the country. The trunks of species of 

 this tribe have been found in considerable 

 numbers near the Isle of Portland, in our own- 

 country, in a fossil state, apparently indicating 

 a time when the climate o England was of 

 a far more tropical character than at present, 

 Many otler facts point to a similar conclusion.* 

 South Africa is the country of geraniums, by 

 far the larger part of the tribe being found 

 here. Five species of geranium, three of Ero- 

 dium, and two hundred and eighty -seven 

 species of Pelargonium inhabit the Cape, and 

 nil the air with their perfume. 



To the genus Pelargonium belong almost all 

 * Not one species of palm is indigenous to the colony. 



