258 A HISTORY OF BIRDS 



The Gruiformes would appear to have been originally striped, 

 inasmuch as traces of a broad median band are visible in the 

 young Japanese Crane, while the young Bustard {Otis tarda) 

 bears a close resemblance to the young Gull, being pale coloured 

 with dark mottlings. 



The young of the Turnices are striped. 



The nestling Rails at the present day are all dusky in colour, 

 yet the young of the Black- tailed Water-hen {Microtribonyx 

 ventralis) shows distinct traces of a median and two lateral 

 stripes. 



The Anseriformes, like the Rails, have now typically uni- 

 formly coloured nestlings. As a rule the upper parts are dark, 

 the ventral light. But the young of the Mallard and its near 

 allies have the upper parts relieved by light-coloured spots 

 — one over the thigh and one behind the wing, which are 

 obviously discontinuous bands. In many Anatidae there is a 

 strongly marked superciliary streak, and a streak passing from 

 the lores to the eye, and behind this to the base of the skull, 

 markings which are evidently remnants of an earlier striped 

 condition. The Sheldrakes depart from this type, having a 

 broad dark median band which passes upwards along the neck 

 and invests the whole of the upper part of the head. A dark 

 patch behind the wing gives the semblance of a white streak 

 on either side of this median band. In the Variegated Shel- 

 drake {Casarca variegata) the dark median band expands 

 over the shoulders to form a transverse band. Whether this 

 peculiar coloration of the downy Sheldrake is a modification 

 of an earlier striped condition or a specialised condition it 

 is not easy to say, but it seems probable that the latter is the 

 case. The under parts, as in all the other Ducks, are white. 

 The downy young of Swans and Geese and of Chauna display 

 no markings, and are either pale grey or pale yellow in colour. 

 But the downy young of the more primitive Geese of the 

 Genera Cereopsis and Clcephaga have, however, it is significant 

 to note, preserved the primitive striping, and the same is true of 

 the Ducks of the Genus Merganetta, thus justifying the inference 

 that the white spots described in more specialised species are 

 remnants of once continuous bands. 



In a number of groups the young are invariably uniformly 

 coloured. But, it is to be noted, these young are all nidicolous ; 



