On this point--the later period at which the parasitical young bird acquires fear of man--and also bearing on the whole subject under discussion, I shall add here some observations I once made on a dove hatched and reared by a pigeon at my home on the pampas. A very large ombú tree grew not far from the dove-cote, and some of the pigeons used to make their nests on the lower horizontal branches. One summer a dove of the most common species, Zenaida maculata, in size a third less than the domestic pigeon, chanced to drop an egg in one of these nests, and a young dove was hatched and reared; and, in due time, when able to fly, it was brought to the dove-cote. I watched it a great deal, and it was evident that this foster-young, though' with the pigeons, was not nor ever would be of them, for it could not take kiudly to their flippant flirty ways. Whenever a male approached it, and with guttural noises and strange gestures made a pompous declaration of amorous feelings, the dove would strike vigorously at its undesirable lover, and drive him off, big as he was; and, as a rule, it would sit apart, afoot or so, from the others. The dove was also a male; but its male companions, with instinct tainted by domestication, were ignorant alike of its sex and different species. Now, it chanced that my pigeons, never being fed and always finding their own living on the plain like wild birds, were, although still domestic, not nearly so tame as pigeons usually are in England. They would not allow a person to approach within two or three yards of them without flying, and if grain was thrown to them they would come to it very suspiciously, or not at all. And, of course, the young pigeons always acquired the exact degree of suspicion shown by the adults as soon as they were able to fly and consort with the others. But the foundling Zenaida did not know what their startled gestures and notes of fear meant when a person approached too near, and as he saw none of his own kind, he did not acquire their suspicious habit. On the contrary, he was perfectly tame, although by parentage a wild bird, and showed no more fear of a man than of a horse. Throughout the winter it remained with the pigeons, going afield every day with them, and returning to the dove-cote; but as spring approached the slight tie which united him to them began to be loosened; their company grew less and less congenial, and he began to lead a solitary life. But he did not go to the trees yet. He came to the house, and his favourite perch was on the low overhanging roof of a vine-covered porch, just over the main entrance. Here he would pass several hours every day, taking no notice of the people passing in and out at all times; and when the weather grew warm he would swell out his breast and coo mournfully by the hour for our pleasure.