Walking over these jagged surfaces of limestone is destructive to any shoes.

A single afternoon of this will do more wear than a month of ordinary use.

Troublesome as these limestones are, as roads, they are ever interesting, because the masses by the roadside present the most astonishing and beautiful forms of waterwear; upon a mass eight or ten feet across, there will be worn a system of ridges and intervening channels, which, in miniature, seems to reproduce the orographic features of the whole country.
[Illustration: WOMEN WITH BABIES; SAN JUAN ZAUTLA] [Illustration: CAIRN, ON ROAD TO COIXTLAHUACA] While we were passing over one of these limestone stretches, a little before reaching the summit, we found a spot of unusual difficulty.

The two pack animals were together, one tied to the tail of the other; the second had several times acted badly, but in passing over this bit of road, he jumped and plunged, so that his pack loosened and slid to one side.

Plunging, kicking, and falling, he dragged down the unfortunate beast to whose tail he was tied; the old rope tugged and creaked, and, for a moment, we expected to see the very tail of the forward animal pulled out, and both packs destroyed by the struggling beasts.
Fortunately, at this moment, the rope itself broke.