114 CAVE AND CI.IFF DWELLERS. 
to forty feet in height. Each arm has 
a score of pulpy ribs along its sides, and 
each rib has a button of thorns every inch 
along its length, each button having 
twenty or twenty-four great thorns stick¬ 
ing from it. I was told that when .a 
hunter is sorely pressed by peccaries, if 
he will climb a pitahaya about ten feet, 
the thorns are so thick and terrible in 
their effect that the peccaries will not 
dare to follow him, hardy and venture¬ 
some as they are. Then there is the 
choya or cholla cactus, about as high as 
one’s waist. You can go around a pita¬ 
haya as you would a tree, but when you 
find a field of chopalla (field of choyas) 
you might as well try to go around the 
atmosphere to get to a given point. 
The cholla will lean over until it breaks 
its back trying to get in your way, so that 
