In the interior of the Argentine every Gaucho is a trailer or _rastreador_. On those vast feeding-grounds of a million cattle, whose tracks intersect each other in every direction, the herdsman can distinguish with unerring accuracy the footprints of his own peculiar charge. When an animal is missing from the herd, he throws himself upon his horse, gallops to the spot where he remembers having seen it last, gazes for a moment upon the trampled soil, and then shoots off for miles across the waste. Every now and then he halts, surveys the trail, and again speeds onward in pursuit. At last he reaches the limits of another _estancia_, and the pasturage of a stranger herd. His eagle eye singles out at a glance the estray; rising in his stirrup, he whirls the lasso for a moment above his head, launches it through the air, and coolly drags the recalcitrant beast away on the homeward trail. He is nothing but a common, comparatively unskilled, _rastreador_. The official trailer is of another stamp. Like his kinsman, the _vaqueano_, he is a personage well convinced of his own importance; grave, reserved, taciturn, whose word is law. Such a one was the famous Calébar, the dreaded thief-taker of the Pampas, the Vidocq of Buenos Ayres. This man during more than forty years exercised his profession in the Republic, and a few years since was living, at an advanced age, not far from Buenos Ayres. There appeared to be concentrated in him the acuteness and keen perceptions of all the brethren of his craft; it was impossible to deceive him; no one whose trail he had once beheld could hope to escape discovery. An adventurous vagabond once entered his house, during his temporary absence on a journey to Buenos Ayres, and purloined his best saddle. When the robbery was discovered, his wife covered the robber's trail with a kneading-trough. Two months later Calébar returned, and was shown the almost obliterated footprint. Months rolled by; the saddle was apparently forgotten; but a year and a half later, as the _rastreador_ was again at Buenos Ayres, a footprint in the street attracted his notice. He followed the trail; passed from street to street and from _plaza_ to _plaza_, and finally entering a house in the suburbs, laid his hand upon the begrimed and worn-out saddle which had once been his own _montura de fiesta_!