190 STUDIES IN BIRD-MIGRATION 



immediately followed by a "rush," and the birds became 

 numerous and general only a little in arrear of their 

 accustomed time. 



In the Hebrides and north-western Scotland, the 

 Swallow is not common, and is mostly observed on 

 passage in small numbers. Occasionally it visits St 

 Kilda in spring. It appears annually in Shetland on 

 migration, chiefly about the middle of May and 

 during June, but is somewhat irregular, both as to the 

 date of its appearance and its numbers. In Ireland the 

 immigrants continue to arrive in considerable numbers 

 until about the middle of May, and in some seasons 

 (1883, 1884, and 1886) as late as the third week of that 

 month, but it is possible that some of these later birds 

 are on passage on their way northwards. 



It is evident from the statistics that the arrival 

 of Swallows on the western sea-board is well in 

 advance of their appearance further to the east. Not 

 only is this so in the south of England, but even in 

 Scotland the districts of "Solway" and "Clyde" almost 

 invariably receive their swallows several days before the 

 "Tweed "and "Forth." 



The spring swallows are recorded as arriving on 

 our southern shores chiefly during the daytime, mainly 

 in pairs, but sometimes as many as six or seven together, 

 and as flying low over the sea, the immigration lasting 

 most of the day. They are also noted as coming in 

 small parties, flock after flock, for several hours in 

 succession, and are usually unaccompanied by any other 

 kinds of birds. At the Eddystone, however, they have 

 on several occasions been observed passing towards the 

 Cornish coast during the hours of darkness, and with 

 other migrants. Thus from midnight to 3 a,m, on 3rd 



