GENERAL NOTE 75 



somewhat tumid skin, commonly yellow in colour, and wax-like in 

 appearance at the base of the beak, and which is pierced by the 

 nostrils. Since a similar, but less conspicuous, band is met with also 

 in the Owls, we might assume that it is in some way necessary to birds 

 of carnivorous habits, but it occurs also in the Parrots ! Another 

 structural feature peculiar to the Accipitres, and more certainly 

 associated with raptorial habits is the long outstanding wing of 

 the lachrymal bone, to the free end of which is commonly added a 

 separate, scale-like plate. This wing forms that projecting shelf, or 

 eaves, over the eye which adds so much to the martial appearance of 

 those birds. It is clear that the function of this is to afford a shade 

 against the glare of light, a very necessary protection where accurate 

 vision is a matter of life or death. In the Vultures, it is significant 

 to note, this wing is far less developed. As with Owls, so with the 

 Accipitres, the iris is either bright yellow, golden brown, or dark 

 brown. This is a curious fact, and one which cannot so far be 

 associated in any way with habit. The Falcons, Buzzards, and Eagles, 

 except the golden-eagle, wherein it is of a golden brown, have a dark 

 brown iris. In the rest of the group it is yellow ; nevertheless closer 

 observation might show some correlation between the two. 



In their habits, as might be supposed from the number of 

 competing species, there is great diversity, though unfortunately our 

 opportunities of studying these have been immensely curtailed by the 

 raids of the game-preserver on the one hand, and the egg-collector 

 on the other. Some, like the kite, have become exterminated ; others, 

 once common, have become exceedingly rare. But all agree in the 

 characters presented by the young at birth, for these are all nidi- 

 colous, and clothed in long, woolly down. This early plumage, unlike 

 that of the Owls, is made up both of pre-penna3 and pre-plumulse. 

 Probably, as in the case of the Owls, it will be found that all develop 

 two generations of this downy plumage, a protoptyle and a mesoptyle 

 generation. In all, save the Ospreys, the down is white or grey in 

 colour, but in the osprey it displays a striped pattern ; evidently a 



