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line of small peninsulas, among which deep bays and arras of the sea 

 flow, with a back-ground intersected in many places by a mountain 

 range, which protects the sea-board from the north and east, and also 

 tends to attract the abundance of moisture rising from the Atlantic, 

 whilst that of the latter is more regular and unbroken, being exposed 

 to those points. The more westerly longitude may have some effect 

 on the flora of the western counties ; but the more equal temperature 

 and greater degree of moisture which prevail there are, no doubt, the 

 principal agents which produce so marked a change. The circum- 

 scribed locality of some of the species is more difficult to account for 

 than vegetation en masse. Why a plant should confine itself to one 

 or two limited spots in a country which possesses many more such 

 places, both in general features and similar geological formation, and 

 be unable to overstep a certain boundary, presents an interesting 

 subject of philosophical inquiry to the generalising mind. For ex- 

 ample, the rare and beautiful orchid, Spiranthes cernua, has only 

 hitherto been discovered to grow in one small field near Berehaven, 

 county Cork. The St. Dabeoc's heath [Menziezia polifolia), another 

 Irish plant, is confined chiefly to the Connemara bogs, and does not, 

 I believe, even occur in Kerry, where every collateral circumstance 

 favourable for its growth seems to be present. The other known 

 Continental localities are the Western Pyrenees and Anjou, in France, 

 where it is said to be confined to the one spot. Gentiana verna, our 

 beautiful spring gentian, which is now so pretty in its wild habitats, 

 and also in our gardens, occupies only a narrow strip across the cen- 

 tres of the western counties, occurring at intervals from Corofin, in the 

 county Clare, to near Holy mount, in the county Mayo, and does not, 

 I believe, extend further to the east, south, or north. Numerous 

 other such instances, even better marked, could easily be pointed out. 

 On a similar mode of reasoning more species of heath may yet be ex- 

 pected to be found in Ireland. Erica multiflora and E. arboi-ea, 

 which grow in parts of France and Spain, may be in some unfre- 

 quented spots among the wilds of Erris, as also may E. slricta, which 

 is already stated to be an Irish species in DeCandolle's Prodromus. 

 " Etiam in Hibernia boreali " are the author's words, which, I fear, 

 is a mistake. The West of Ireland would be a much more likely 

 locality for it to occur along with so many of its kindred. 



' David Moore. 



