ON THE BOTANICAL SUBDIVISION OF IRELAND. 61 that they should be followed ; but it is not always possible to follow them, on account of other considerations. The convenience of county-divisions is so great, that, except in the subdividing of a large county, it does not appear desirable to forsake county boundaries. Equalisation of Areas. — It is also desirable that, so far as possible, the country should be divided into portions of approximately equal area ; but here again the less the arrangement by counties is disturbed the better. Utilisation of past or future Botanical Work. — It is manifestly desirable that the scheme as regards subdivision of counties should harmonise with the subdivisions used, or to be used, in published or future county or local floras ; since this will save a large amount of labour when it comes to working out the flora of each vice- county. Nature of Boundaries. — Where a new boundary-line is required, it is desirable that it should be something conspicuous — a railway, road, or river — in order that it may easily be found in the field ; an imaginary line, such as a straight line between two places, though it looks very well on a map, is often difiicult to trace in the field. Let me now take up in turn each of the cases in which the plan suggested differs from that proposed by Babington, explain the nature of the change, and give the reasons. Cork. — Is now divided into three vice-counties (3, 4, 5), by two N.W. and S.E. lines. Babington divided it into two vice-counties, one much larger than the other, by the east and west course of the River Sullane and its continuation the River Lee. In that useful little flora. The Flowering Plants and Ferns of the County Cork (1883), the author, Rev. Thomas Allin, departs from Babington 's boundary, and adopts instead " a line drawn along the Killarney Junction Railway from the border of Co. Kerry to Millstreet, thence running across the country in a straight line to Macroom, thence in a similar line to Bandon, and from that town, following the Bandon River, to the sea." '^' This line appears to have been wisely chosen, dividing the western mountainous portion of the county, with its Atlantic, Highland and American plants, from the more level tract, with its calcicole and Germanic species. The latter district (1747 square miles), being still considerably larger than the largest of the counties which it is not proposed to subdivide, is conveniently divided into two by the Great Southern and Western Railway from Charleville to Cork, and thence by the western sliore of Cork Harbour to the ocean ; this line forms approximately the western boundary of the Carboniferous limestone. The great county of Cork is thus divided into three parts of almost equal area, the size of each being about that of an average Irish county. As regards the division of Co. Cork, I have had the advantage of the hearty co-operation of Mr. R. A. Phillips, whose knowledge of the Cork flora is well-known, and who suggested to me the sub-division of the county adopted in this paper. Kerry. — In Babington's scheme Kerry is divided into two vice-
- Op. cit., Introduction, p. xii.
