to press it against its breast as before, though making the most desperate efforts to do so. Wedging its head between the bark and the ground, the bird now stood still more perpendicularly upright on its breast (or rather, in this case, on its head) than it had done before, and in this position shoved and shouldered away most desperately. After each effort it would lie a little, as if exhausted, then waddle to the other egg, and settle itself upon it; but in a minute or two it would return to the one it had seemingly abandoned, and repeat its efforts to extricate it. I must have watched the bird make at least half a dozen of these attempts; but at last, after nearly half an hour, an idea occurred to it (or rather it altered its tactics then, as the idea may have come sooner). Again going to the properly placed egg, the bird, instead of covering it as before, began to move it to the other one in the way that I have described. "If the mountain will not go to Mohammed, Mohammed must go to the mountain." That was clearly the process of reasoning, and, seeing how set the bird's mind had been on one course of action, how it had toiled and struggled and returned to its efforts again and again, its sudden adoption of another plan shows, I think, both intelligence and versatility. It, in fact, acted just as an intelligent man would have acted. It tried to do the best thing till convinced it was impossible, and then did the second best. Still, we cannot any more, than in the case of the man, assume that the alternative course of action was not in the bird's mind from the beginning. Having got the two eggs together again, the bird appeared to me (for it was now too dark to observe accurately) to be trying to push the piece of bark away backwards with its wings, feet, and tail. It certainly propelled itself backwards against the edge, after the manner—observed by Jenner, and now, I believe, authenticated by photography—the young Cuckoo ejects its foster brothers and sisters from the nest. Finally, at 9.40, it flew away. I then went out to look, and saw that the bird had been successful in its efforts to a certain extent. The two eggs lay together, and though not quite on the same level, and though the piece of bark was still in the way of one of them, it might still, though not with ease, have sat on them both. However, had I left them as they were, I have no doubt that the birds would have worked away till matters were quite