The proverbial present of a white elephant is paralleled in bird life by the gift of the cuckoo's egg. The bird whose nest is chosen never deserts the strange changeling, but seems to feel feeding the young cuckoo to be a sacred duty, and sees its own young ejected and perishing without apparent concern. My attention was called one spring to a robin's nest made in a stubble rick; there chanced to be a slight hollow in the side of the tick, and this had been enlarged. A cuckoo laid her egg in the nest, and as it happened to be near some cowsheds it was found and watched. When the young bird began to get fledged some sticks were inserted in the rick so as to form a cage, that it might not escape, and there the cuckoo grew to maturity and to full feather. All the while the labour undergone by the robins in supplying the wide throat of the cuckoo with food was something incredible. It was only necessary to wait a very few minutes before one or other came, but the voracious creature seemed never satisfied; he was bigger than both his foster-parents put together, and they waited on him like slaves. It was really distressing to see their unrewarded toil. Now, no argument will ever convince me that the robin or the wagtail, or any other bird in whose nest the cuckoo lays its egg, can ever confound the intruding progeny with its own offspring. Irrespective of size, the plumage is so different; and there is another reason why they must know the two apart: the cuckoo as he grows larger begins to resemble the hawk, of which all birds are well known to feel the greatest terror. They will pursue a cuckoo exactly as they will a hawk. I will not say that that is because they mistake it for a hawk, for the longer I observe the more I am convinced that birds and animals often act from causes quite distinct from those which at first sight appear sufficient to account for their motions. But about the fact of the lesser birds chasing the cuckoo there is no doubt. Are they endeavouring to drive her away that she may not lay her egg in either of their nests? In any case it is clear that birds do recognise the cuckoo as something distinct from themselves, and therefore I will never believe that the foster-parent for a moment supposes the young cuckoo to be its own offspring.