CACTUS OF ECONOMIC PLANTS. 75 



Cactus, a name originally given by Theoplirastus (b.c. 288) 

 to a spiny plant ; but what that plant was modern investigation 

 has failed to ascertain. Linnseus adapted it for the name of a 

 genus of spiny plants, which in modern botany rex^resents the 

 Cactus family (Cactaceae), of which there are many species. The 

 whole, with one or two exceptions, are natives of the West 

 Indian Islands and the American continent, where they are 

 found in greater or less abundance in the different regions, from 

 the Eocky Mountains and Oregon in the North, and Chili and 

 Paraguay in the South. They grow on rocks and in hot dry 

 sterile places; some love moisture, growing on trees. They vary 

 greatly in size and form. On account of the substance of which 

 they are formed consisting of soft fleshy matter, they are called 

 succulent plants. Their leafless and unplant-like forms led 

 them to become early objects of curiosity in this country. C. 

 Opuntia is recorded as having been cultivated in his garden by 

 John Gerard at Holborn before 1596. In Alton's Hortus Keivensis, 

 published 1789, twenty-two species are recorded, and in the 

 second edition, 1813, this number was only increased by two. 

 They not only formed objects of curiosity in botanic gardens, 

 but also in the hothouses of many private gardens. About 

 1830, species chiefly of the section Echinocactus began to be 

 introduced from Mexico, which were patronised by a few rich 

 amateurs, not only in this country, but also on the Continent, 

 who vied with each other in the possession of new importations, 

 and prices as high as £10, £20, or even £30, were given for single 

 plants. This mania lasted only the lifetime of the original ama- 

 teurs, and private collections of Cactcce in this country are now for 

 the most part a thing of the past. About 800 species of Cactece are 

 described in books, of which upwards of 700 names are recorded 

 in nurserymen's catalogues. This number is consequent on 

 different names being given to the same species by different 

 authors, and the various forms of the same being also described 

 as distinct species. During the above period the Kew collection 

 was greatly increased by purchases, as also by exchanges ; but, 

 after much trouble and expense, the collection in its best days 



