210 
CAVE AND CLIFF DWELLERS . 
leg over with a slight quiver, as he turns 
around. 
All these mountain trails are full of 
little round, hard stones about the size of 
marbles, and even larger ones, hidden 
underneath a carpeting of pine needles. 
These are liable to make a mule stumble 
if two feet are on the stones at once, but 
this, is very seldom, although they always 
go sliding over them on the steeper trails. 
It is wonderful how these round rocks, 
hidden under the pine needles on the 
trail or off it, will throw a human being 
prostrate if he dismounts a few minutes 
to take a walk on a slope and stretch his 
stiffened limbs. Of course the mule, 
under headway, is liable to walk over him 
before it can stop or the person pick him¬ 
self up. 
There is another pastime in which the 
