490 THE GANNET 



either side. From the fork, or division of the lower man- 

 dibles, a bare dilatable skin, which is nearly black, extends 

 downwards about 4.5 inches, sometimes more, occasionally 

 less. The mouth, more particularly the palate and tongue, 

 are also black, both in a young Gannet and in an adult, 

 with a bluish tint in the former. 



Colour of the Feet. — The feet are dark grey, relieved by 

 a curious form of ornamentation — a Kne of apple-green 

 commencing on the tarsus and running along the ridge 

 of each toe. Possibly these bright lines (which are made 

 up of oblong scales) once had some other object than that 

 of mere ornamentation ; but here we find ourselves in a 

 field of speculation. In a young Gannet they are dark grey, 

 but the pattern is the same — even in a nestHng that much 

 is identical. I could perceive no hue of green in these 

 leg-fines at the age of eighteen months, but at twenty -five 

 months it was becoming apparent.* 



* On June 12 th, 1911, I had an opportunity of seeing three adult Black - 

 tailed Gannets, Sula capensis, just received by the Zoological Society, 

 and was glad of an occasion for noting that they had just the same stripes 

 of green upon their legs and toes as our S. bassana has. The pattern 

 was also the same as far as could be seen without actually handling the 

 birds. The tract of bare skin round their eyes was pale blue, the eye 

 itself nearly white, lores black, beak a horny-white, perhaps a little 

 begrimed. Some of these particulars are given in ' ' The Fauna of South 

 Africa" (IV., p. 18). The Australian S. serrator has the same stripes on 

 its legs, according to Sir W. BuUer (" Birds of New Zealand," II., p. 177). 



