Horse and Man. 357 



stant use, or the slow cumulative process of natural 

 selection, has served to develop a keenness of sense 

 almost preternatural. The vulture's eye, with all the 

 advantage derived from the vulture's vast elevation 

 above the scene surveyed, is not so far-reaching as 

 the sense of smell in the pampa horse. A common 

 phenomenon on the pampas is a sudden migration 

 of the horses of a district to some distant place. 

 This occurs in seasons of drought, when grass or 

 water fails. The horses migrate to some district 

 where, from showers having fallen or other circum- 

 stances, 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 



