wrist-bones may be found. And the "palm-bones," which 

 in the adult are welded together, are here quite separate. 

 This stage, then, carries us back towards the ancestral, 

 reptilian fore-hmb used for walking, or perhaps for climbing. 

 And there is another sign of this earher reptilian period to be 

 foimd in such a wing. At the tip of the thumb and first 

 finger in unhatched ducks, game-birds, and water-hens, for 

 example, you wiU find a small claw. By hatching time the 

 claw of the first finger will have disappeared, but it is stiU 

 retained in the case of the duck and the water-hen. In the 

 adults of aJl three you will rarely find more than the claw of 

 the thumb : and this now serves no useftd purpose whatever. 



Indeed, there seem to be only two tribes which have any 

 use for wing-claws during nestling life. One of these is 

 represented by the gallinules, that is to say, the coots, and 

 water-hens, and their kind. You may test this whenever you 

 have the good fortune to capture a young water-hen. Place 

 him outside the nest, and especially if it happens to be a 

 httle raised, you wiU see him make his way back, using feet, 

 wing-claws, and beak. His wings, it will be noticed, at this 

 stage are used as fore-legs. The other tribe is represented 

 by that strange bird the hoatzin of the Amazon. Here the 

 two claws are really large, and they play a quite important 

 part in his early life. 



For the young hoatzin is hatched in a nursery — a crude 



ii8 



