364 ISLAND LIFE 



rigorous an examination is about what we sliould expect in 

 comparison with the hmited amount of speciality we have 

 seen to exist in other groups. The three American species 

 which inhabit the extreme west and north-west of the 

 British Isles, but are not found on the continent of Europe 

 are especially interesting, because they demonstrate the 

 existence of some iDeculiar conditions such as would help 

 to explain the presence of the other peculiar species. 

 Whether we suppose these American forms to have 

 migrated from America to Europe before the glacial epoch, 

 or to be the remnants of a vegetation once spread over the 

 north, temperate zone, we can only explain their j^resence 

 with us and not further east by something favourable 

 either in our insular climate or in the limited competition 

 due to our comparative poverty in species. 



About half of the peculiar forms are found in the 

 extreme west or north of Britain or in Ireland, where 

 peculiar insular conditions are at a maximum ; and tlie 

 influence of these conditions is further shown by the 

 number of species of West or South European plants which 

 occur in the same districts. 



We may here notice the interesting fact that Ireland 

 possesses no less than twenty species or sub-species of 

 flowering plants not found in Britain, and some of these 

 may be altogether peculiar. As a whole they show the 

 effect of the pre-eminently mild and insular climate of 

 Ireland in extending the range of some south European 

 species. The following list of these plants, for which I am 

 indebted to Mr. A. G. More, with a few remarks on their 

 distribution, will be found interesting : — 

 List of Irish Floweking Plants which are xot found ix Britain. 



1. Poly gala vulgaris {var. grandiflora). Sligo. 



2. Campanula rotundifolia {var. speciosa). W. Ireland. 



3. Arciiaria ciliata. W. Ireland (also Auvergne, Pyrenees, Crete). 



4. Saxifraga umhrosa. W. Ireland (also Pyrenees, N. Spain, Portngal). 

 f). ,, gcum. S. W. Ireland (also Pyrenees). 



6. ,, hirstcta. S. W. Ireland (also Pyrenees). 



7. Inula salicina. W. Ireland (Scandinavia, ]\Iiddle and South Europe). 



8. Erica mcditcrranea. W. Ireland (W. France, Spain, Portugal). 



9. ,, macTcaiana {t/ilndix snh.-s]).)\^. Ireland (Spain). 



10. Arbutus uncdo. S. W. Ireland (W. of France, Spain, Portugal and 



shores of JMediterranean). 



11. Dabcocia iJolifolia. W. Ireland (W. of France, Spain and Portugal). 



