108 Proceedings of the Royal Physical Society. 



panied by these particulars, so far as available; and of 

 course the more minute and perfect these are, the better, 

 and the sooner will they be likely to prove of scientific 

 value. 



Now, in order in some measure to supply the omission in 

 the above record of the Little Gull, I have referred to our 

 migration schedules for 1883. 



At Dhuheartach on 29th October the wind was S.S.W. 

 with haze, and wild geese were seen flying S.E., while 

 stonechats and thrushes were flying round the lantern at 5 

 a.m., or resting on the rocks at 12 noon. 



On the 31st October the wind had gone round to JST.KW., 

 fresh with haze, when one woodcock — the first mentioned on 

 the schedule since 8th April — was killed by striking the 

 lantern ; and a blackbird was seen " flying E." This is the 

 latest scheduled record I have at present from this locality. 

 I will merely remark here that this " flying E " or " flying 

 S.E." is the normal direction of flight at Dhuheartach of 

 birds on migration, as already shown in our reports. 



Again, at MacArthur's Head, Islay, migration was pro- 

 ceeding on the 30th, and winds were from W. to S. with haze. 

 On our East Coasts also prevailing winds were southerly and 

 westerly, and a great migration took place at Isle of May 

 during the last week in October. 



From these parallel data we arrive at the conclusion that 

 the Little Gull exhibited to-night had got into the groove or 

 regular current of general migration of other species, and 

 the wind being that particularly favourable to migrants to 

 our coasts, as has been shown in our reports, it carried on 

 with the stream. Being a young bird of the year upon its 

 first migration, and having probably no older guide of its 

 own species, or having been lost previously, perhaps, from a 

 flock of its own species, it carried along with the other 

 migrants beyond the usual limits of its autumnal range, and 

 then rested on the sandy and marshy island of Bernera in 

 the Sound of Harris, which, I know from personal observa- 

 tion, is the first spot on that line which is admirably 

 adapted to the habits of the bird in question. It passed 

 southward to North Uist, because it would not naturally fly 



