The horses migrate to some district where, from showers having fallen or other circumstances, there is a better supply of food and drink. A slight breeze blowing from the more favoured region, which may be forty or fifty miles away, or even much further, is enough to start them off. Yet, during the scorching days of midsummer, very little moisture or smell of grass can possibly reach them from such a distance. Another phenomenon, even more striking, is familiar to every frontiersman. For some reason, the gaucho horse manifests the greatest terror at an Indian invasion. No doubt his fear is, in part at any rate, an associate feeling, the coming of the Indians being always a time of excitement and com-motion, sweeping like a great wave over the country; houses are in flames, families flying, cattle being driven at frantic speed to places of greater safety. Be this as it may, long before the marauders reach the settlement (often when they are still a whole day's journey from it) the horses take the alarm and come wildly flying in: the contagion quickly spreads to the horned cattle, and a general stampede ensues. The gauchos maintain that the horses _smell_ the Indians. I believe they are right, for when passing a distant Indian camp, from which the wind blew, the horses driven before me have suddenly taken fright and run away, leading me a chase of many miles. The explanation that ostriches, deer, and other fleet animals driven in before the invaders might be the cause of the stampede cannot be accepted, since the horses are familiar with the sight of these animals flying from their gaucho hunters.