THE GIANT CACTUS. 



643 



older plants have been more than a century and a half in grow- 

 ing. The size of the plant is not always a fair criterion of its 

 age, as plants eight to ten feet 

 high, growing from the granite 

 rocks on the southern slopes of 

 the Santa Catalina Mountains, 

 are- older than plants four or five 

 times larger growing in deep 

 canons or in yards about the 

 city, where the water supply is 

 not so completely withdrawn. 

 The ability, however, of this 

 plant to withstand prolonged 

 drought is very great. Its enor- 

 mous mass of succulent tissue, 

 protected by a thick epidermis, 

 enables it to maintain the ac- 

 cumulated moisture for an al- 

 most indefinite period, even after 

 every source of outside moisture 

 has been dried up. A plant may 

 be taken up, exposed to the hot, 

 dry air for months, and when 

 replaced in the soil continue to 

 grow, having suffered little ap- 

 parent injury. Living speci- 

 mens, weighing several hundred 

 pounds, may be packed in boxes 

 and shipped to Europe and other 

 foreign countries, without injury 

 to their vitality. A few years 

 ago a specimen some eight feet 

 high was placed in the window 

 of one of the Tucson shops. 

 Some eighteen months later it 

 was found on examination to 

 still contain a large amount of 

 moisture. Its vitality is further 

 illustrated by the fact that a foot 

 or more of the top may be cut 

 from the plant in early spring 

 and sent across the continent, flowers developing on the detached 

 portion several weeks after it has reached its destination. 



A number of birds, including the Gila woodpecker, the red- 

 shafted flicker, and the golden flicker, excavate great holes in the 

 soft tissues in which they build their nests. Later the abandoned 



GIANT CACTUS ( Oereus giganteus). 

 (Engelm.) 



