504 DESERT PLANTS AS A SOURCE OF DRINKING WATER. 



the extraction of water from a l)isnao-a accordino- to the primitive 

 process and by one of the aborioines themselves. The localit}'^ was in 

 the State of Sonora, Mexico, at a point about 12 kilometers (8 miles) 

 west of the railroad station of Torres. Upon request a Papago Indian, 

 the guide of the party, exhibited the operation. The cactus used was 

 a specimen of bisnaga {Eelunocactus emoryi) with which the region 

 abounds. 



The plant selected was about 1 meter (3it feet) high and 0.5 meter 

 (20 inches) in diameter. Its top was first sliced oli', exposing- the white 

 interior (pi. i). It was evident that this was saturated with water, 

 but the structure of the tissue was such that the water did not exude 

 of its own accord. The Indian cut a stake of palo verde {Parh'msonia 

 micropliijlla) about 7.5 centimeters (3 inches) in diameter at the larger 

 and blunt end, and wnth this proceeded to mash the white flesh of the 

 cactus into a pulp. As the churning progressed a bowl was formed 

 in the top of the cactus, and when a suitable quantity of pulp had 

 accumulated in it the Indian, taking this up handful by handful, 

 squeezed out the water into the bowl, throwing the rejected pulp upon 

 the ground. 



From the upper 20 centimeters (about 8 inches) of the cactus about 

 3 liters (3 quarts) of water was obtained. Its flavor maj- be described 

 as very slightly salty and somewhat herbaceous. Any really thirsty 

 traveler would have drunk it without hesitation, and our Papago, 

 although he had had plenty of water from the supply we carried, 

 drank the cactus juice w4th evident pleasure (pi. ii). 



A bisnaga of approximately spherical form furnishes a more pala- 

 table water than the cylindrical specimens many years older, and care 

 is taken to use for a masher a wood which has no bitter, resinous, or 

 poisonous qualities. No deleterious efi'ect is caused, our Indian stated, 

 through drinking a quantitv of the water, unless one subjects himself 

 immediately afterwards to violent ph3^sical exercise. The natives use 

 the cactus water, if need be, for mixing bread, and evidently it could 

 be devoted to an}' camp use. 



An interesting correlation is to be noted betw^een the palatable flesh 

 of the bisnagas and their efl'ective protection against grazing animals 

 through their impenetrable armor of hooked and rigid spines. With- 

 out such protection the bisnaga would be doomed to early extinction 

 by such animals as required a continual supply of moist, herbaceous 

 food. Other cactuses, on the contrarv, which have a bitter and nause- 

 ating juice, often have only a very imperfect protection by spines, as 

 the giant QixoXxx^ {Cereus (/iganteus) and the sina {PUocereufi schottif). 

 One cactus, the peyote {Lophopho7X( '(v!JUarn,sii)^ has no spines what- 

 ever at maturity. In appearance it is as plump and juicy as an apple; 

 yet, as is demonstrated by its abundance in certain localities, it is amply 



