112 



CASE Observe specimens of the stem of the Turk's Cap 

 58. Cactus {Melocactus communis^ Link and Otto), from the 

 West Indies ; also plants of Echinocactus cylindraceus, 

 EngeL, with long curved spines. 



No. 289. Calcium oxalate deposited in immense 

 quantities in the tissues of various Cacti (Cereus spp.). 



No. 290. Portions of the Old Man Cactus {Cereus 

 senilis, Salra-Dyck), so called from the long white hairs 

 which crown the columnar stems. One species in Western 

 North America {C. giganteus, Engel.) attains a height of 

 45 to 50 feet. 

 CASE ^^ *h^ upper shelves of the first compartment are 

 59^ fruits, &c., of various species of Cereus, chiefly from 

 Venezuela, also portions of stem and a photograph of 

 C. gigauteus, EngeL, and flowers of species of PhyJlocactus 

 and Bhijosalis. 



No. 291. Woody portion of stem of Opuntla Bigelovii, 

 Engel., from Arizona. 



No. 292. Cochineal. Small hemipterous insects 

 subsisting upon species of Opujitia and iVo^^aZea, to which 

 the wingless females attach themselves. Cultivated in 

 the Canary Islands, Mexico, and Brazil, for the sake of 

 their rich crimson dye, from which carmine and the lakes 

 of the artist are made. Different kinds of Cochineal are 

 known in commerce, as silver grain, black, white, &c. 

 Specimens are exhibited from Teneriffe (which is the 

 principal source of British imports), Mexico, East Indies, 

 Java, &c. A view in the Cochineal Gardens or Nopaleries 

 at Santa Cruz, Teneriffe, is shown in the Korth Gallery 

 (No. 522). 2,388 cwts. of Cochineal were imported into 

 the United Kinsrdom during 1905 of the value of £2o,718. 

 The remainder of this compartment is filled with fruits of 

 various species of Opxmtia. 



No. 293. Fibrous portions of stems of NoPAL {Opunila 

 Tuna, Mill.), made into various ornamental articles. From 

 Algeria. 



't>" 



Fig-Marigold Order {Ficoideae). A tribe of succu- 

 lent plants, remarkably characteristic of the hot desert 



