Animals of all classes, old and young, shrink with instinctive fear from any strange object approaching them. A piece of newspaper carried accidentally by the wind is as great an object of terror to an inexperienced young bird as a buzzard sweeping down with death in its talons. Among birds not yet able to fly there are, however, some curious exceptions; thus the young of most owls and pigeons are excited to anger rather than fear, and, puffing themselves up, snap and strike at an intruder with their beaks. Other fledglings simply shrink down in the nest or squat close on the ground, their fear, apparently, being in proportion to the suddenness with which the strange animal or object comes on them; but, if the deadliest enemy approaches with slow caution, as snakes do--and snakes must be very ancient enemies to birds--there is no fear or suspicion shown, even when the enemy is in full view and about to strike. This, it will be understood, is when no warning-cry is uttered by the parent bird. This shrinking, and, in some cases, hiding from an object corning swiftly towards them, is the "wildness_"_ of young birds, which, Darwin says again, is greater in wild than in domestic species. Of the extreme tameness of the young rhea I have already spoken; I have also observed young tinamous, plovers, coots, &c., hatched by fowls, and found them as incapable of distinguishing friend from foe as the young of domestic birds. The only difference between the young of wild and tame is that the former are, as a rule, much more sprightly and active. But there are many exceptions; and if this greater alertness and activity is what is meant by "wildness," then the young of some wild birds--rhea, crested screamer, &c.--are actually much tamer than our newly-hatched chickens and ducklings.