ORN.—I find I must multiply examples. Examine young ducks which have been hatched under a hen; they no sooner quit the shell, than they fly to their natural element, the water, in spite of the great anxiety and terror of their foster-parent, who in vain repeats that sound to which her natural children are so obedient. Being in the water, they seize insects of every kind, which they can only know from their instincts to be good for food; and when they are hatched in the May-fly season, they pursue these large ephemeræ with the greatest avidity, and make them their favourite food. It is impossible, I think, to explain these facts, except by supposing, that they depend upon feelings or desires in the animals developed with their organs, which are not acquired, and which are absolutely instinctive. I will mention another instance. A friend of mine was travelling in the interior of Ceylon; on the banks of a lake he saw some fragments of shells of the eggs of the alligator, and heard a subterraneous sound: his curiosity was excited, and he was induced to search beneath the surface of the sand: besides two or three young animals lately come from the shell, he found several eggs which were still entire: he broke the shell of one of them, when a young alligator came forth, apparently perfect in all its functions and motions; and when my friend touched it with a stick, it assumed a threatning aspect, and bit the stick with violence. It made towards the water, which (though born by the influence of the sunbeams on the burning sand) it seemed to know was its natural and hereditary domain. Here is an animal which, deserted by its parents, and entirely submitted to the mercy of nature and the elements, must die if it had to acquire its knowledge; but all its powers are given, all its wants supplied; and even its means of offence and defence implanted by strong and perfect instincts. I will mention one fact more. Swallows, quails, and many other birds, migrate in large flocks when their usual food becomes scarce; and in these cases it may be said (I anticipate a remark of Physicus), that the phenomenon depends upon imitation, and that the young birds follow the old ones who have before made the same flight. But I will select the young cuckoo for an unexceptionable example of the instinctive nature of this quality. He is produced from an egg deposited by his mother in the nest of another bird, generally the hedge sparrow. He destroys all the other young ones hatched in the same nest, and is supplied with food by his foster-parent, after he has deprived her of all her natural offspring. Quite solitary, he is no sooner able to fly than he quits the country of his birth, and finds his way, with no other guide than his instinct, to a land where his parents had gone many weeks before him; and he is not pressed to make this migration by want of food, for the insects and grains on which he feeds are still abundant. The whole history of the