In Patagonia [Footnote: Patagonia: the southern part of Argentine Republic.] I added something to my small stock of private facts concerning eyes--their appearance, color, and expression--and vision, subjects which have had a mild attraction for me as long as I can remember. When, as a boy, I mixed with the gauchos [Footnote: Gauchos: these people are of Spanish-American descent. They are the native inhabitants of the pampas, and live chiefly by cattle-raising.] of the pampas, [Footnote: Pampas: vast plains in the southern part of South America, chiefly in the Argentine Republic.] there was one among them who greatly awed me by his appearance and character. He was distinguished among his fellows by his tallness, the thickness of his eyebrows and the great length of his crow-black beard, the form and length of his "facon," or knife, which was nothing but a sword worn knife-wise, and the ballads he composed, in which were recounted, in a harsh tuneless voice to the strum-strum of a guitar, the hand-to-hand combats he had had with others of his class--fighters and desperadoes--and in which he had always been the victor, for his adversaries had all been slain to a man. But his eyes, his most wonderful feature, impressed me more than anything else; for one was black and the other dark blue. All other strange and extranatural things in nature, of which I had personal knowledge, as, for instance, mushrooms growing in rings, and the shrinking of the sensitive plant when touched, and Will-o'-the-wisps, and crowing hens, and the murderous attack of social birds and beasts on one of their fellows, seemed less strange and wonderful than the fact that this man's eyes did not correspond, but were the eyes of two men, as if there had been two natures and souls in one body. My astonishment was, perhaps, not unaccountable, when we reflect that the eye is to us the window of the mind or soul, that it expresses the soul, and is, as it were, the soul itself materialized. Some person lately published in England a book entitled "Soul-Shapes," treating not only of the shapes of souls but also of their color. The letter-press of this work interests me less than the colored plates adorning it. Passing over the mixed and vari-colored souls, which resemble, in the illustrations, colored maps in an atlas, we come to the blue soul, for which the author has a very special regard. Its blue is like that of the commonest type of blue eye. This curious fancy of a blue soul probably originated in the close association of eye and soul in the mind. It is worthy of note that while the mixed and other colored souls seem very much out of shape, like an old felt hat or a stranded jelly fish, the pure colored blue soul is round, like an iris, and only wanted a pupil to be made an eye. Here again I recall an incident of my boyhood, and am not sure that it was not this that first gave me an interest in the subject.