224 THE ZOOLOGIST. 



weathers on any marine rock island lying in the migration route, 

 I venture to say that the ornithologist who elected to take up his 

 abode at such a site could see much of what I have already put 

 forward in this paper. But such shelter is not obtainable — at 

 all events on rugged wave-swept rocks — in other than in the 

 dwelling apartments of lighthouses. Indeed, were it not for the 

 most kind sanction of the Commissioners of Irish Lights whereby I 

 have been enabled to become housed securely against the ravages 

 of wave and storm, I never could have culled the knowledge 

 which I now have put forward in this paper on a special phase 

 of bird migration. Were one to study only the phenomena of 

 birds assembling and making contact with the lantern at night, 

 then a vast amount of most instructive information would never 

 come to hand. I would also lay emphasis on the fact that the 

 topographical aspect of the Eock itself demands the closest 

 study. Thus its relative height above the sea-level may have a 

 more or less direct influence in inducing passing migrants to 

 break their journey and alight ; while the question as to what 

 water and food can be obtained would exercise a varying influence 

 on the length of stay which a bird might make ; these and 

 several other points, which can only be studied when residing on 

 the Rock, affect the whole question of the features of diurnal 

 migration in a marked degree. Such important facts, however, 

 could hardly be expected to enter the minds of ornithologists who, 

 while writing on the subject of bird-migration at light-stations, 

 had not thoroughly familiarised themselves with the special 

 topography of each station. This fact is brought home very 

 clearly in Mr. Moffat's note entitled " The Tree-Pipit as an Irish 

 Bird."* Here, in entering a caveat against my suggestion that 

 the two Tree-Pipits which I recently obtained at the Tuskar 

 Rock might be Irish emigrants, he draws analogies between 

 the occurrences of several species rare to Ireland obtained 

 on autumnal migration only (as recorded by Mr. Barrington)t 

 and the occurrence of the two Tree-Pipits above mentioned which 

 I obtained. He considers all as autumnal stragglers, and all 

 killed at light-stations, as though always attracted by the light, 

 adding that the tendency to come to the lights in autumn and 



|: Vide ' Irish Naturalist,' vol. xxi. December, 1912, pp. 246-247. 

 f Vide ' Migrations of Birds at Irish Light Stations,' pp. 11, 72, 181. 



