VOL. VI.] STUDIES IN BIRD MIGRATION. 83 



The last chapter of the first volume gives an interesting 

 and fascinating account of a month spent at the Eddystone 

 Lighthouse. The author points out that this sojourn was 

 undertaken in order to ascertain something of the emigratory- 

 movements from our shores in autumn, and that this station 

 was chosen as being Avell isolated from the south coast, and 

 giving an additional opportunity of seeing what migration was 

 passing in the night. The substance of his experiences and 

 results has already appeared in the Ibis for April, 1902, 

 pp. 246-69, and so requires no further notice ; added, however, 

 is a full record of every species which came under notice, and 

 an interesting photograph of the famous towers. Since 

 Mr. Clarke's visit the light has evidently been altered from 

 " the enormous " power of 80,000 candles to one of 292,500 

 candles ! 



In the autumn of 1903 the author undertook a month's 

 stay on the Kentish Knock Light-vessel, twenty-one miles 

 from the nearest points of the Kent and Essex coast, it being 

 in a suitable position for studying the passage of migrants 

 crossing the southern part of the North Sea. The chapter 

 devoted to this is practically a reprint of a paper in the Ibis 

 for 1904, pp. 112-42. Like the experiences at the Eddy- 

 stone the account is extremely interesting, and shows what 

 a lot of migration can be seen in suitably-chosen spots, albeit 

 uncomfortable ones. Mr. Clarke twice makes reference 

 (Vol. I., p. 290 and Vol. II., p. 36) to two races of Starling, 

 one with a purple head obtained at the Eddystone exclu- 

 sively, and the other A\'ith a green head obtained only at 

 the Kentish Knock ; the former was thought to be an immi- 

 grant race, but surely the latter were also immigrants ? We 

 have studied this question of two races with some care, 

 and feel certain that the two races do not exist ; we have 

 seen British- breeding birds as well as east-coast migrants, 

 with heads of both colours, and in a few specimens tinges 

 of both colours prevail on the same bird. We think it is 

 probably a question of wear or age, or perhaps both. It must 

 be remembered, moreover, that the purple gloss will change 

 to green on altering the position of the light from in front 

 to behind the observer. 



The next three chapters are devoted to an account of Fair 

 Isle and its migrants. This small island of 2^ square miles, 

 lying midway between Orkney and Shetland, appeared to 

 the author to present unrivalled chances for observing the 

 passage of birds to and from the north o^^•ing to its isolated 

 position, its smallness of size, and to the fact that it is situated 

 beyond the breeding-range of most of our own avifauna. The 



