326 The Naturalist in La Plata.
is discoverable. In such a case, the animal, goaded by its instinctive fear, turns to the one spot that horses avoid; and although that spot has hitherto been fearful to him, the old fear is forgotten in the present and far more vivid one; the vicinity of his master's house represents a solitary place to him, and he seeks it, just as the stricken deer seeks the interior of some close forest, oblivious for the time, in its anxiety to escape from the herd, of the dangers lurking in it, and which he formerly avoided.
I have not set this explanation down merely because it does credit to my friend's ingenuity, but because it strikes me that it is the only alternative explanation that can be given of the animal's action in coming home to die. Another fact concerning the ill-tamed and barbarously treated horses of the pampas, which, to my mind, strengthens the view I have taken, remains to be mentioned. It is not an uncommon thing for one of these horses, after escaping, saddled and bridled, and wandering about for anight or night and day on the plains, to return of its own accord to the house. It is clear that in a case of this kind the animal comes home to seek relief. I have known one horse that always had to be hunted like a wild animal to be caught, and that invariably after being saddled tried to break loose, to return in this way to the gate after wandering about, saddled and bridled, for over twenty hours in uncomfortable freedom.
The action of the riding-horse returning to a master he is accustomed to fly from, as from an enemy, to be released of saddle and bridle, is, no doubt more intelligent than that of the dying horse
The Dying Huanaco. 327
coming home to be relieved from his sufferings, but the motive is the same in both cases; at the gate the only pain the animal has ever experienced has invariably begun, and there it has ended, and when the spur of some new pain afflicts him--new and yet like the old--it is to the well-remembered hated gate that it urges him.
To return to the huanaco. After tracing the dying instinct back to its hypothetical origin--namely, a habit acquired by the animal in some past period of seeking refuge from some kind of pain and danger at a certain spot, it is only natural to speculate a little further as to the nature of that danger and of the conditions the animal existed in.
If the huanaco is as old on the earth as its antique generalized form have led naturalists to suppose, we can well believe that it has survived not only a great many lost mammalian types, but many changes in the conditions of its life. Let us then imagine that at some remote period a change took place in the climate of Patagonia, and that it became colder and colder, owing to some cause affecting only that portion of the antarctic region; such a cause, for instance, as a great accumulation of icebergs on the northern shores of the antarctic continent, extending century by century until a large portion of the now open sea became blocked up with solid ice. If the change was gradual and the snow became deeper each winter and lasted longer, an intelligent, gregarious, and exceedingly hardy and active animal like the huanaco, able to exist on the driest woody fibres, would stand the beat chance of maintaining its existence in such altered conditions,