502 CHAINS OF CIRCUMSTANCE 



peaty land not far from West Linton, known as the White 

 Moss. In 1890 this area was covered with a close growth of 

 heather: it was indeed a typical heather moor with peat and 

 moisture underneath. In 1892 or 1893, according to a former 

 gamekeeper on the estate, a man of intelligence and close ob- 

 servation, a few pairs of Black-headed Gulls came to nest 

 upon the Moss. These were protected and encouraged by 

 the proprietor for the sake of his Pheasants, the eggs of the 

 Gulls being used for feeding the gamebirds. The collection of 

 eggs was made systematically, only the early clutches being 

 taken, while the last clutch was invariably left to hatch. As 

 a result of protection the Gulls increased enormously in 

 numbers, so that in 1897, Mr William Evans regarded the 

 colony as the most populous in the district, and in 1904 

 came to the conclusion that there could not be fewer than 

 1500 to. 2000 pairs of birds. 



With the extension of the gullery, the vegetation gradu- 

 ally underwent a noticeable change. At first the heather 

 (Calluna) gradually disappeared and its place was taken by 

 coarse grass, which grew so rankly that the villagers cut 

 from it heavy crops of hay. Then the grass gave way to a 

 dense growth of rushes (Juncus glomeratus] amongst which, 

 after a time, sprang up weeds of cultivation, which had be- 

 fore been unnoticed in this peaty ground. Of these some 

 thrived with extraordinary vigour, and a forest of docks 

 (Rumex) arose which almost choked the rushes and the 

 disappearing grass. 



So crowded did the original gullery become, that an 

 offshoot from it settled upon a part of the White Moss half 

 a mile away, where the surface also was entirely covered 

 with heather (Calluna). Here similar changes took place 

 in the vegetation the heather was successively replaced 

 by rough grass, then by rushes, and lastly docks predomi- 

 nated. Nothing could be more striking than to visit these 

 areas in spring before the new year's growth has commenced, 

 and to see, clear cut in the midst of a black heather moor, 

 a circular patch of withered tawny-yellow stems and grass 

 of the past season the site of the gullery (Fig. 88). Closer 

 inspection shows that the margin of the gullery shades, as 

 one would expect, into the surrounding heather, the borders 

 of which are broken by scattered tussocks of grass becoming 



