WEST COAST OF SCOTLAND. 55 



fan of migration, if I may so express it. In 1879 and 1881, in 

 ^Scotland, we had a closed-fan of migration. The natural result 

 of the wide-spread fan is continuous streams of migration and 

 no rushes ; that of the closed-fan great throbs and rushes, for 

 birds prefer to travel with a beam wind and wait for favourable 

 winds, and do not often voluntarily start on their flight with a 

 following wind. The occurrence of the white-spotted form of 

 Blue-throated Warbler after a succession of tremendous S.E. 

 gales, culminating in the dreadful hurricane of Oct. 14th, clearly 

 shows, I think, that acts of voluntary migration do not take place 

 in following winds. This Bluethroat was caught up and borne 

 away, nolens volens, and our Mid-Atlantic notes in 1880 show 

 similar abnormal results from prevalence of easterly gales. It 

 is to be regretted that we have no returns this season from Mid- 

 Atlantic, owing to Mr. Anderson's engagements in the Mediter- 

 ranean. Even total absence or perfectly negative evidence of 

 birds in Mid-Atlantic would have given us a valuable standpoint 

 as compared with the great mortality of 1880.* 



The lines of migration indicated in my Keport of Scotland 

 for 1879 and 1880, and conclusions drawn from statistics of these 

 two years, appear to me to be borne out by those of 1881, as 

 regards the semicircular form of the migration, an account 

 of which I have already given in our last report {op. cit., 

 pp. 18, 19). 



The subject of heights of lanterns and their colours as 

 attractions for birds has not developed as yet any fresh facts, but, 

 with the conviction that they will yet do so, I still retain the 

 table of heights given. Actual experiment, however, would very 

 likely very soon set this part of the subject at rest (vide General 

 Remarks, East Coast of Scotland Report, 1880, pp. 19, 20). A 

 light-vessel or two placed in an equally favourable position with, 

 let us say, the Isle of May or the Bell Rock on the east coast, or 



* I may mention here that I have made an endeavour to enhst the 

 whaHng captains of Dundee in our service, but have not yet learned whether 

 it has been successful or not. I had copies of the British Association 

 Abstract reprinted in a cheap form, and I sent a bundle to Dundee for 

 distribution amongst the captains. Should Mr. Anderson yet give us any 

 Mediterranean statistics, they can appear as an Appendix to our Report 

 for 1882. 



