Many species of cactus, and the nopal, or prickly pear, especially, are full of watery sap, which trickles out in a stream when they are pierced. In these thirsty regions, when springs and brooks are dry, the cattle bite them to get at the moisture, regardless of the thorns. On the north coast of Africa the camels delight in crunching the juicy leaves of the same plant. I have often been amused in watching the camel-drivers’ efforts to get their trains of laden beasts along the narrow sandy lanes of Tangier, between hedges of prickly pears, where the camels with their long necks could reach the tempting lobes on both sides of the way.
In this thirsty season, while the cattle in the Mexican plains derive moisture from the cactus, the aloe provides for man a substitute for water. It frequently happened to us to go from rancho to rancho asking for water in vain, though pulque was to be had in abundance.