1918.] On the Birds of the Isle of May. 247 



is teji^meu. This subject was made from a barb cut from a 

 Pink-footed Goose primary with magnification of 50 times. 



Plate VII. fig. 2 is an attempt to show the superficial 

 stru(;ture of the tegmen of a Pink-footed Goose. It was 

 made with a magnification of 500 times. 



At the commencement of these notes it was stated that 

 I was engaged on the photographic analysis of a feather. 

 These notes 011 the tegmen form a portion of the whole 

 work, which it is ho[)ed to publish before long in complete 

 form. 



XIV. — The Birds nf the Isle of May : A Migration Study. 

 By Evelyn V. Baxter and Li^onoka Jeffrey Rintoul. 



Introduction. 

 The Isle of May has long been known as a very favourable 

 station for the observation of bird migration. It stands at 

 the entrance of the Firth of Forth, and is separated from 

 the land by a distance of five miles on the north and ten 

 on the south. It is about a mile long and half a mile 

 wide ; the rocks on the west and south-MCst sides are very 

 precipitous, rising to a maximum height of 180 feet above 

 the sea ; they are intersected by caves, are basaltic in forma- 

 tion, and of a crumbling consistency, making any attempt 

 at cliff-climbing dangerous. On the north and east the 

 land slopes gradually down to the water's edge, broken by 

 inlets on the eastern side. P;irts of the island were for- 

 merly cultivated, but now the greater portion is covered 

 with rough grass interspersed with rocks : here and there, 

 patches of thistles, nettles, and hemlock occur, and these, 

 together with the gardens of the lightkeepers, form the only 

 covert available for the Ijirds which visit the island. On the 

 west of the* island the clifls are broken by a ravine, the 

 precipitous sides of which rise to a height of 100 feet, and 

 in which lies a partly artificial lake; small pools are found 

 in the shallow depressions on the grass-grown plateaux and 

 rock-pools close to sea-level. 



