`Historicus nascitur, non fit.' I am painfully aware that neither my calling nor election in this matter are the least sure. Certain it is that in youth, when alone the historian or the horseman may be formed, I did little to fit myself for writing history. Wandering about the countries of which now I treat, I had almost as little object in my travels as a Gaucho of the outside `camps'. I never took a note on any subject under heaven, nor kept a diary, by means of which, my youth departed and the countries I once knew so well transmogrified, I could, sitting beside the fire, read and enjoy the sadness of revisiting, in my mind's eye,