The nursing or fostering instinct which is so prominent in the imitative play of little girls deserves more attention. A special section is devoted to such play among animals in my former work, but I admit that I am myself somewhat sceptical in regard to some of the examples quoted there, though I was most careful to get the testimony of trustworthy investigators. Among animals, moreover, some sorts of nursing play are wanting, such, for instance, as that in which a lifeless object is treated as a veritable infant.[576] The feeding of young birds of a second brood by their older brothers and sisters seems to me entitled to be called a nursing play, and Naumann observed this in the case of water wagtails. Altum reports the same behaviour by canary birds, and vouches for having seen young water wagtails who were still wearing their first feathers feed young cuckoos.[577] That this is a play can scarcely be questioned, and it must be imitative since the parent birds are taken as models, but whether it is dramatic illusion play is another question and a doubtful one, for there is always actual feeding with actual food; not, as with children, a mere pretence. Yet I am very doubtful whether there would be any nursing plays among children without parental models, and for that reason it has been included among imitative plays in this book instead of being given a separate section. We then conclude that the maternal instinct is present in little girls, but first attains expression in play on the rise of the imitative impulse. We have a direct analogue to the bird examples when an older child assumes the rôle of mother to a younger with purely playful and imitative motives. Dramatic illusion first comes in when sham activity is involved, as may be the case with dolls, other children, or even adults as the subjects. We must conclude, then, that the imitative impulse is fully developed only when imagination supplements the copy. Baldwin gives a particularly pretty instance of dramatic nursing play where the older sister takes the part of mother to the younger.[578]