396 THE ZOOLOGIST. 



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 seem- 

 ingly 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 



