Of the birds I am acquainted with, the beautiful jacana (Parra jacana) appears to come into the world with its faculties and powers in the most advanced state. It is, in fact, ready to begin active life from the very moment of leaving the shell, as I once accidentally observed. I found a nest on a small mound of earth in a shallow lagoon, containing four eggs, with the shells already chipped by the birds in them. Two yards from the small nest mound there was a second mound covered with coarse grass. I got off my horse to examine the nest, and the old birds, excited beyond measure, fluttered round me close by pouring out their shrill rapidly-reiterated cries in an unbroken stream, sounding very much like a policeman's rattle. While I was looking closely at one of the eggs lying on the palm of my hand, all at once the cracked shell parted, and at the same moment the young bird leaped from my hand and fell into the water. I am quite sure that the young bird's sudden escape from the shell and my hand was the result of a violent effort on its part to free itself; and it was doubtless inspired to make the effort by the loud persistent screaming of the parent birds, which it heard while in the shell. Stooping to pick it up to save it from perishing, I soon saw that my assistance was not required, for immediately on dropping into the water, it put out its neck, and with the body nearly submerged, like a wounded duck trying to escape observation, it swam rapidly to the second small mound I have mentioned, and, escaping from the water, concealed itself in the grass, lying close and perfectly motionless like a young plover. In the case of the pampa or creolla sheep, I have shown that during its long, rough life in La Plata, this variety has in some measure recovered the natural vigour and ability to maintain existence in adverse circumstances of its wild ancestors. As much can be said of the creolla fowl of the pampas; and some observations of mine on the habits of this variety will perhaps serve to throw light on a vexed question of Natural History--namely, the cackling of the hen after laying, an instinct which has been described as "useless" and "disadvantageous." In fowls that live unconfined, and which are allowed to lay where they like, the instinct, as we know it, is certainly detrimental, since egg-eating dogs and pigs soon learn the cause of the outcry, and acquire a habit of rushing off to find the egg when they hear it. The question then arises: Does the wild jungle fowl possess the same pernicious instinct?