CACTUS. 87 



prickly pear, or Indian % of commerce, is the product of 

 Opuutia vulgaris, a very handsome greenhouse plant that 

 grows in a succession of green oval disks dotted with 

 spines, and produces in the early days of summer a glorious 

 show of large, satiny, yellow flowers. The much-valued 

 cochineal is the produce of an insect, the Coccus cacti, that 

 lives on the cochineal cactus, Ojauntia cochinillifera, a 

 Mexican plant now largely established in the Canaries and 

 in Java, but which has been put in the shade somewhat by 

 the competition of aniline dyes, which have at least the 

 merit of cheapness. 



In the cultivation of cactuses, the requirements are few 

 and simple, but must not be trifled with. Cactuses demand 

 a somewhat calcareous sandy soil, with the most perfect 

 drainage, for damp is their greatest enemy. It is too 

 much the rule with cultivators to employ a very poor soil ; 

 but this is a mistake. A really generous soil is requisite 

 to ensure free growth and fine flowers ; but the drainage 

 must always be the first consideration, for that being 

 faulty, all other conditions, however suitable, are of no 

 value whatever. At all times cactuses should be in the 

 fullest light possible, and throughout the winter they 

 should have no water, or no more than will just suffice to 

 prevent shrivelling. 



The summer treatment should include liberal supplies 

 of water, and in the case of fine specimens that show 

 promise of producing a great crop of flowers, weak liquid 

 manure may be given until the flowering is over. It is a 

 common error to keep these plants on short commons all 

 the summer long, the result being a poor growth and very 

 few flowers. They want warmth, light, air, and substan- 

 tial food, and, as a rule, should be under glass the whole 



