To our eyes one young robin (meaning out of the nest--on the hedge) is almost identical with another young robin; to our ears the querulous cry of one for food is confusingly like that of another: yet the various parent birds easily distinguish, recognise, and feed their own young. Then to suppose that, with such powers of observation--with the keenness of vision that can detect an insect or a worm moving in the grass from a branch twenty feet or more above it, and detect it while to all appearance engaged in watching your approach--to suppose that the robin does not know that the cuckoo is not of its order is past credit. The robin is much too intelligent. Why, then, does he feed the intruder? There is something here approaching to the sentiment of humanity, as we should call it, towards the fellow-creature. The cuckoo remained in the cage for some time after it had attained sufficient size to shift for itself, but the robins did not desert it: they clearly understood that while thus confined it had no power of obtaining food and must starve. Unfortunately, a cat at last discovered the cuckoo, which was found on the ground dead but not eaten. The robins came to the spot afterwards--not with food, but as if they missed their charge. The easy explanation of a blind instinct is not satisfactory to me. On the other hand, the doctrine of heredity hardly explains the facts, because how few birds' ancestors can have had experience in cuckoo-rearing? There is no analogy with the cases of goats and other animals suckling strange species; because in those instances there is the motive--at all events in the beginning--of relief from the painful pressure of the milk. But the robins had no such interested motive: all their interests were to get rid of their visitor. May we not suppose, then, that what was begun through the operation of hereditary instinct, i.e., the feeding of the cuckoo, while still small and before the young robins had been ejected, was continued from an affection that gradually grew up for the helpless intruder? Higher sentiments than those usually attributed to the birds and beasts of the field may, I think, be traced in some of their actions. To the number of those birds whose call is more or less apparently ventriloquial the partridge may be added; for when they are assembling in the evening at the roosting-place their calls in the stubble often sound some way to the right or left of the real position of the bird, which presently appears emerging from the turnips ten or fifteen yards farther up than was judged by the ear. It is not really ventriloquial, but caused by the rapid movements and by the circumstance of the bird being out of sight.