BIRDS. 



233 



Finally, between the times of its earlier advents and dispersal, and say that of 1893, 

 it may be said to have become general, as shown in a 5, and with decreasing density. 



In 4 a dispersal is shown where ' the lines of least and greatest resistance ' 

 in Spey valley are represented by the narrowings of and widenings of the course 

 at the various defiles we have described in the earlier portions of the book — amongst 

 which are the Pass of Sourdan and Lower Craigellachie in Speyside, of Upper Craigel- 

 lachie in Strathspey, and Craigdhu and Kinrara in Badenoch. In a 3 a wave is 

 shown by the fining down of the central streak or valley, and an increase at the 

 extremity before the flood, so to speak, dams back the surplus into the side valleys 

 represented in a 4. 



Although we have applied these diagrams to illustrate the dispersal of the Red- 

 start, as being a very good example for illustration, yet the above remarks may be 

 equally applied to several other species whose distribution is on the same lines. 



[Ruticilla t\tys, Scoj). Black Redstart. 



* A bird which, in four different years, was seen in the Elgin district, 

 I think, must have been this species. Some forty or fifty years 

 ago it brought out its young at No. 3 South Street, Elgin, and 

 more lately at the Manse of Elgin, in an apricot-tree. In 1856 and 

 1858 it bred at the Manse of Birnie. In one of these years I had 

 one in my hand, having been caught under a net on the wall. It 

 appeared to be a young one. Both it and those I saw at 3 South 

 Street, Elgin, were darker than the Spotted Flycatcher. Still, 

 however strong in my opinion, perhaps some further evidence 

 would be desirable ' (Note by Dr. Gordon of Bimie). A specimen 

 of this bird was obtained in Cullen, Banffshire, by Mr. Thomas 

 Edward in 1851 (Naturalist, vol. i. p. 145). 



Edward relates that he was only aware of two of this species 

 having been seen in the county of Banff. Edward wrote in 1876. 

 Mr. Robert Gray quotes the above record of the Cullen bird (Birds 

 of the West of Scotland, p. 84, 1871). Not any trace of the speci- 

 men is now to be found (Harvie-Brown). We see no reason why 

 specimens of this species may not occur at times, seeing that they 

 have occurred both to the north (Pentland Skerries, etc.) and to 

 the south (Isle of May and Forth); but meanwhile, unless wo 

 receive a positive record before going to press, we must follow our 

 rule of square brackets to date.] 



Cyanecula suecica (L.). Blue-throated Warbler. 



On September 15th, 1890, Mr. H. Brinsley Brook, whom we had 

 the pleasure of afterwards meeting at Forres in 1893, saw at 



