112 THE SCOTTISH NATURALIST 



of the estuary, and in the first days of October 1916 many 

 Swallows were seen on westward flight at Culross on the 

 Forth. It might point to an overland passage line to the 

 west coast, and certainly a consideration of the map of 

 Scotland suggests the possibility of such a line. The sight 

 of a House-martin flying over the estuary from the south- 

 east, and on reaching the north bank rising higher and 

 changing its course to travel parallel to it, in the orange glow 

 of an October sunset, convinces one that there is something 

 to find. 



So far, all inquiries, principally confined to Perthshire, 

 have failed to trace the line of flight. As it stands, I have 

 only traced the flights some eight miles west of Dundee, but 

 at that point the passage was as prominent as at Dundee. 

 Mugdrum Island and the surrounding reed-beds are thronged 

 in autumn with flocks of Swallows and Martins, and the 

 departure of these and the direction of their flight seems 

 unrecorded. I saw, on one occasion, while sailing down the 

 river below Newburgh, large flocks flying in mist and rain to 

 the west late in the evening in mid- September, at which 

 time the maximum movement is being reached, but this may 

 have been purely accidental. I have no detailed information 

 for that locality. As another indication of the possible ex- 

 istence of a cross-Scotland passage line, I would point out 

 that all local records of movements of the Swift of any 

 magnitude have been from the west in spring and to the 

 west in autumn. Only once has immigration in spring been 

 recorded from the east, and that on a very small scale. 



I leave the matter as it stands, having no further informa- 

 tion, hoping that others may be able to add more facts, or 

 better still, explain the meaning of this movement. 



Blue Shark in Largo Bay. On 30th December 19 17 I 

 found a Blue Shark (Carcharias glaucus) between three and four 

 feet long, lying on the sand in Largo Bay. This is the third found 

 there in the last eight years, and was considerably smaller than either 

 of the other two. Evelyn V. Baxter, Largo, Fife. 



