146 CAVE AND CLIFF DWELLERS. 
little attention is paid even to such a 
ratio, or to any other in agriculture, and 
only the most careful observation or in¬ 
quiry can elicit the facts necessary for a 
basis of proper conjecture. 
A Mexican diligence is ornamented 
with an assistant to the driver in the 
shape of a nimble young fellow, whose 
business it is to throw stones at the mules. 
He occupies the front seat alongside the 
driver, and whenever the mules have the 
appearance of commencing to walk— 
which occurs about every half minute— 
he jumps nimbly to the ground, makes a 
dash ahead for the leaders, with his hand-s 
and pockets full of stones, and pelts the 
unfortunate beasts well. Of course they 
make a tremendous burst of speed, and 
he grasps the straps on the side of the 
coach and swings himself on top; then 
