132 The Scottish Naturalist. 



" As this is the fourth report issued by the Committee, we may 

 perhaps, with the mass of facts at our disposal, be expected to 

 draw deductions which, if they do not explain, may serve at least 

 to throw some light on the causes influencing the migration of 

 birds. We might reasonably reply that the work undertaken by 

 us was not to theorise, or attempt explanations, but simply to 

 collect facts and tabulate them ; this we have endeavoured to do 

 in the shortest and simplest manner consistent with accuracy of 

 detail. There is, however, one circumstance which can scarcely 

 fail to present itself to those who have gone carefully into the 

 reports issued by the Committee, namely, the marvellous persist- 

 ency with which, year by year, birds follow the same lines, or 

 great highways, of migration, when approaching or leaving our 

 shores. The constancy of these periodical phenomena is sugges- 

 tive of some settled law or principle governing the movement. It 

 is clearly evident, from the facts already at our disposal, that there 

 are two distinct migrations going forward at the same time, one 

 the ordinary flow in the spring and ebb in the autumn across the 

 whole of Europe. A great migratory wave moves to and from the 

 nesting-quarters of the birds in the coldest part of their range, 

 north-east in the spring, and south-west in the autumn. Quite 

 independent of this there is a continual stream of immigrants, 

 week by week and month by month, to the eastern shores of these 

 islands, coming directly across Europe from east to west, or more 

 commonly from points south of east to north of west, and the re- 

 verse in the spring. These immigrants are mainly composed of 

 those common and well-known species which annually make these 

 islands their winter-quarters, and as a rule take the place of our 

 summer birds. They come in one broad stream, but denser on 

 some special lines or highways than others. Cutting the line of 

 ordinary migration nearly at right angles, one flank brushes the 

 Orkney and Shetland islands, pouring through the Pentland Firth, 

 even touching the distant Faroes ; the southern wing crosses the 

 Channel islands, shaping its course in a north-westerly direction to 

 the English coast." 



During the meeting the question of the relation of the scientific 

 societies of Great Britain to the British Association and to one 

 another, as also the best means of utilising the work done by them 

 to make it of permanent value, was considered by a committee of 

 the Association, and also by a meeting of delegates from a number 

 of the Societies. The final report of the Committee will soon be 

 submitted to the Council of the Association. It will form the 

 subject of an article in the next number of this Magazine. 



It is probably known to all our readers that the meeting in 

 1884 is to be held in Montreal in Canada; and that of 1885 in 

 Aberdeen. 



CRYPTOGAMIC SOCIETY OF SCOTLAND. 



The Cryptogamic Society of Scotland held its ninth Annual 



