Clare Island Survey — Phanerogamia. 10 87 



To come back to the main question, we have to admit that we are not in a 

 position to say definitely whether birds could have introduced that very large 

 proportion of the flora of Clare Ireland which could not owe its presence to 

 wind or water. Out of 393 species inhabiting the island, not more than 15 

 are at all likely to have been introduced by water, nor more than 50 by 

 wind. We must also deduct about 55 species which were or may have been 

 introduced directly or indirectly by man. It seems unlikely that the total 

 balance, numbering about 270 species, belonging to many different orders, 

 and possessing seeds and seed-vessels of all sizes, shapes, and characters, were 

 brought over by the rather scanty avifauna, even though the distance from 

 the mainland is not great. 



We must remember at the same time that many species arrived on the 

 island probably in early times, when the local distribution of plants was 

 different from what it is at present. Thus, I doubt if anyone would claim 

 that Saxifraga, Geum was introduced directly by either natural or artificial 

 agency from Kerry, or Silene acaulis from Sligo ; but they might have been 

 introduced, say, by birds, from former neighbouring colonies which are long 

 since extinct. By the majority of naturalists, discontinuous distribution is 

 regarded as being generally relict distribution, not incipient colonization due 

 to long-distance dispersal (see ante, p. 56). 



A case which came under my own notice may be quoted, 1 as it shows both 

 how conspicuous a part birds may play in plant-dispersal, and how little right 

 one has to generalize from a particular instance. Near Frankford in King's 

 County a colony of Black-headed Gulls was breeding in the centre of a large 

 peat-bog, about half a mile from the surrounding farm-land. The guano and 

 trampling of the birds had in some spots destroyed the bog- vegetation, and in 

 its place a coarse herbage sprang up, which comprised — 



Banunculus acris. Veronica Charnaedrys. 



Capsella Bursa-pastoris. V. arvensis. 



Cerastium triviale. Prunella vulgaris. 



C. glomeratum. Plantago major. 



Sagina procumbens. Atriplex sp. 



Trifolium repens. Polygonum Persicaria. 



Epilobium obseurum. Bumes Acetosella. 



Daucus Carota. Juncus effusus. 



Bellis perennis. Holcus lanatus. 



Senecio vulgaris. Poa annua. 



Hypoehaeris radicata. 

 Not one of these plants was native on the bog, while all were common on 



1 Puaegek, Irish Topographical Botany, p. xsxviii, 1901. 



