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 himself up. There is another pastime in which the Mexican mule delights, and in which you won't. It likes to deviate enough to go under every low-branched tree on the trail, and so universal is this trait of character that the trail seems to lead from one low tree or vine to another, just as the mule has a mind to make it. The dodging of limbs and branches among the pines, cypresses, and oaks in the high lands was not so bad, but down in the _tierra caliente_ or hot lands, where brambly mesquite and thorny vines were tearing crescents out of your clothes until you looked like a group of Turkish ensigns, it was much more monotonous. The beast I was compelled to ride had one ear cut off near the head, and looked top-heavy in the extreme. As a mule's ears make up a goodly portion of it, as seen in elevation from the saddle on its back, I was always frightened when he approached a cliff on the unabridged side, and instinctively leaned in to counterpoise the heavy weight that I thought might drag us over the precipice. He was familiarly known by the party as "Old Steamboat," "Old Lumber Yard," and other names indicating these characteristics; but he was large and so was I, and he fell to my lot. When I first saw his abbreviated auricular appendage, as a member of the "Society for the Prevention of Cruelty to Mules," I felt incensed upon hearing that it had been lost by the cut of a whip in the hands of a previous driver; but before we had been acquainted a week I had transferred all my sympathy from the mule to the man, whoever he may have been. On the level ground this mule was slower than the Mexican cook, who took fifteen minutes to wash a spoon; but on a perilous path of half a foot in width, on a dizzy precipice, the way he could box the compass with the lone ear, so as to catch some faint sound at which he could get frightened at this inopportune time, made me wish I could cut off the other ear at about the third cervical vertebra.