She cannot possibly know what effect the stuffing of the pollen on to the stigma exercises, or indeed whether it have any effect at all. And yet generation after generation these moths collect the pollen from the anthers and bear it to the stigma. Spence’s words “without knowledge of the end in view” are amply justified in this case, as in other cases of typically instinctive behaviour. III.--THE INSTINCTIVE BEHAVIOUR OF YOUNG BIRDS Since it is easy to hatch birds of many species in an incubator, and to rear them under conditions which not only afford facilities for observation but exclude parental influence, their study has special advantages. One can with some approach to accuracy distinguish the instinctive from the acquired factors in their behaviour.[34] [Illustration: FIG. 15.--Newly-hatched Chick swimming.] The callow young of such birds as pigeons, jays, and thrushes are hatched in a helpless condition, and require constant and assiduous ministration to their elementary organic needs. Most of their instincts are of the deferred type. But pheasants, plovers, moor-hens, domestic chicks, and ducklings, with many others, are active soon after birth, and exhibit powers of complex co-ordination, with little or no practice of the necessary limb-movements. They walk and balance the body so soon and so well as to show us that this mode of procedure is congenital, and has not to be gradually acquired through the guidance of experience. Young water-birds swim with neat and orderly strokes the very first time they are gently placed in water. Even little chicks a day or two old can swim well. Dr. Thorndike, who draws attention to this fact,[35] appears to accept the view, suggested by Dr. Bashford Dean, that the movements are not those of swimming but only of running. I have carefully watched the action through the glass walls of a tank and compared it with that of a young moor-hen. In the two cases it is quite similar in type, and the type appears to be different from that of running, though it is perhaps hard to distinguish the two. In any case, the hand over hand action is well co-ordinated, and is very different from a mere excited struggle. Chicks twenty-six hours old taken straight from the incubator drawer, before they had taken food, made directly for the side of the tank and tried to scramble out. They gradually sank deeper through the wetting of the down, but could keep afloat for from two to three minutes. I have made observations on chicks of various ages from twenty-four hours to a month, and find in all cases similar results; but with the older birds the flapping of the wings and more vigorous action cause them to get water-logged more rapidly. There is some apparent distress with cries; but less than one might expect under the circumstances. For the purposes of the above illustration Mr. Charles Whymper had before him a sketch I made of the leg-action, and instantaneous photographs of the chicks swimming for