9 18 Proceedings of the Royal Irish Academy. 



In support of this conclusion, the occurrence of tree or shade species along 

 the entire western coast-line, on most of the islands, and on the mountain- 

 ranges far above the present tree limit, may be cited. Barrington 1 found Scilla 

 nutans, Luzula sylvatica, and Primula vulgaris on the Great Blasket ; while 

 Praeger records Digitalis -purpurea and Lonicera Periclymenum from the same 

 island. 2 The Clare Island forest and shade flora has already been referred to. 

 From Inishturk, a rocky island standing out in the Atlantic in the vicinity of 

 Clare Island, Praeger 3 records Bdula pubescens, Corylus Avellana, Ilex aaui- 

 folium, Populus tremula, Salic cinerea, and the following shade plants : — 

 Lonicera Periclymenum, Primula vulgaris, Luzula maxima ; while Juniperus 

 nana occurs both on Inishturk and Achill Island, although absent from Clare 

 Island. On Inishbofin, Praeger 4 found Aspen and Mountain Ash, and Luzula 

 maxima ; and the same observer records Lonicera Periclymenum and Luzula 

 erecta from the Mullet, 5 and Luzula maxima on the extreme west of Achill 

 Island." Hart 7 recorded various shade plants, as — Sanicula europoea, Scilla 

 nutans, Luzula maxima, Digitalis purpurea, Primula vulgaris, Lonicera 

 Periclymenum, &c, at various elevations up to 2640 feet on the mountains 

 of Mayo and Galway; while Oak was found up to 750 feet and Hazel up to 

 1100 feet. These records, while not absolute proofs of the existence of woods 

 at an earlier period, prove the survival of plants so closely associated with 

 shade that they furnish the student of plant associations with evidence that 

 is practically convincing on this point when taken in conjunction with other 

 facts. 



Another point of importance in connexion with these relics of previous 

 woodland extension is the more or less universal sterility of the soils on which 

 they exist. While they are usually absent from the peat blanket which 

 appears to wipe out everything but a characteristic peat flora, Oak and Hazel 

 are frequently found on rock detritus, and in crevices of rock slopes ; and 

 while their survival on these sites is easily understood, it is difficult to 

 imagine their establishing themselves under existing conditions. Oak and 

 Hazel woods now growing on talus and Boulder-clay ground in the extreme 

 west are not merely in a decadent and stunted condition, showing little 

 vegetative and still less propagative vigour, but the surface is invariably 

 covered with a surface flora of Heather, A r accinium, Molinia, Sphagnum, and 

 other plants, forming the early stages of peat formation, and the conditions 

 are the reverse of those favourable for the establishment of Oak and Hazel, 



1 Proc. R. I. A., series ii, vol. iii. 2 Irish Naturalist, vol. xxi. 



3 Irish Naturalist, vol. xv. 4 Irish Naturalist, vol. xx. 



* Irish Naturalist, vol. xiv. 6 Irish Naturalist, vol, xiii. ; Proc. R. I. A., series ii, vol, 



