2 THE ZOOLOGIST 



on the mainland and on the island was quite mild, yet Eobins 

 were much more numerous than they had been there in the 

 spring and summer. When I lived in Dublin I always noted a 

 decided increase of Eobins in the autumn and winter, i. e. from 

 October onward. It seems very likely, then, that a considerable 

 number of Eobins immigrate to Ireland as well as to Great 

 Britain at the fall of the year. The puzzling feature is this : 

 Why have I seen and collected so few birds during my one 

 hundred and twenty-four days' residence at the Tuskar Light 

 Station ? In its bearing, in its movements, in its bold confiding 

 nature, and in its plumage the Eobin attracts notice. In fact, 

 few birds ought to be less easily overlooked. And yet I observed 

 only seven Eobins altogether — six at the lantern and one on the 

 rock, all of which I collected. Beyond one other bird observed 

 on the rock by Mr. Granville, no other records were made of the 

 presence of this species during my stay at the Tuskar Light- 

 Station. I have not as yet had opportunities of learning some- 

 thing of the features of migration of this bird at other light- 

 stations along the eastern seaboard of Ireland, where differences in 

 the powers of illumination, in the speed of revolution of the rays 

 in revolving lights, in the height of the lantern from the ground, 

 may act as determining factors in a more or less degree in 

 attracting this species to the lantern. Hence it is quite obvious 

 that one cannot state with any degree of certainty that the 

 cause of the Eobin's absence from the lantern depends upon its 

 peculiar powers of sight, so that it can withstand to a considerable 

 extent the intense brilliancy of the rays without being dazzled, 

 and thereby can largely avoid coming in contact with the lantern- 

 glass. However, on the other hand, from a close study made 

 repeatedly on many species, I can state with considerable confi- 

 dence that, under the mesmeric enchantment of the luminous 

 beams, different birds do behave very differently. 



In the case of the Eobin, I noticed that the six specimens 

 which approached the light acted very similarly. They came up 

 quietly, fluttered down the glass, and were easily picked off. 

 While under the impression that I may have seen more Eobins 

 in the rays other than those collected, I cannot at the same time 

 feel convinced in this matter, and my hypothesis is framed 

 almost entirely on the fact that I saw birds about the same size 



