452 BRITISH BIRDS. 



Family PODICIPEDID^E, OR GREBES. 



The Grebes are a small well-defined group of birds, whose relationship 

 to the Divers appears to have been hitherto generally admitted, though it 

 is very difficult for an egg-collector to realize the fact. Forbes was of 

 opinion that after the Divers the Ducks were the nearest relations of the 

 Grebes. Sclater unites them in an order with the Divers and the Auks, 

 an alliance equally foreign to the notions of the field ornithologist. Gadow 

 associates them with the Divers as one family (the Cormorants and the 

 Penguins being two others), which may be regarded as greatly specialized 

 descendants of the group of which the Ducks are the least modified sur- 

 viving forms. Newton, in a highly characteristic Glads tonian sentence*, 

 appears to regard the relationship of the Grebes from an agnostic point 

 of view. 



The Grebes are schizognathous in the arrangement of their palatal 

 bones, which doubtless resemble those of the Divers, as no difference in 

 this respect has been pointed out by Huxley. They also resemble the 

 Divers very closely in the arrangement of their feather-tracts. The 

 Grebes like the Divers have only one small notch on each side of the pos- 

 terior margin of the sternum, but the lateral processes extend beyond the 

 central projection. The myology of the two families also presents some 

 points of difference. 



Grebes are born covered with down, and after a few hours are capable of 

 swimming. Young in first plumage moult the feathers of the head and 

 neck in the first autumn, and they, as well as adults, moult all their small 

 feathers in spring ; and in autumn adult birds have a complete moult, the 

 wing-feathers, like those of the Ducks, being cast so rapidly that for some 

 weeks the birds are unable to fly. 



The Grebes are formed expressly for diving ; their plumage is soft and 

 silky; their legs are placed far behind; their tarsi are very short and 



* " Mr. Sclater thinks the Pygopodes seein to form a natural transition between the 

 Gulls and the Penguins. The affinity of the Alcidce or Auks (and through them the Divers 

 or Colymbidce) to the Gulls may be a matter beyond doubt, and there appears to be ground 

 for considering them to be the degraded offspring of the former ; but to the present writer 

 it appears questionable whether the Grebes, Podicipedidce, have any real affinity to the two 

 families with which they are usually associated, and this is a point deserving of more 

 attention on the part of morphologists than it has hitherto received " (Newton, ' Encycl. 

 Brit., Ornithology,' p. 45). It is to be presumed that " them " refers to the Auks and 

 " the former " to the Gulls. 



