286- The Irish Natiualist. November, 



well as of surface, aud consequently less diversity of flora. The appli- 

 cation of Watson's well-known "types of distribution " to Ireland is 

 productive of some interesting results, and shows a considerable diver- 

 sityof range in the same groups of plants in Great Britain and in Ireland. 

 The "English " plants of Watson reach in Ireland their maximum on 

 the east coast in Dublin, Wicklow, and Wexford, and are also remark- 

 ably abundant in Clare. Watson's "Scottish'' plants show a more 

 uniform range in Ireland. They attain their maximum in the northern 

 maritime counties. Thence they spread down the west coast in con- 

 siderable abundance as far as the Shannon mouth, while on the east 

 coast they decrease rapidly south of Down. Wntson's Highland" 

 plants are found chiefly in the west. The}' attain their maximum 

 on the comparatively low hills of Donegal and West Gal way, and are 

 only sparingly represented on the higher mountains in the east, such as 

 those of Down, Wicklow, and Tipperary. Watson's " Germanic " group 

 is practically non-existent in Ireland ; the fragments which reached 

 that countr}' have a quite irregular distribution, with a maximum in Clare. 

 The " Atlantic " plants have a more definite distribution in Ireland, rang- 

 ing round the coast, aud showing an increase southward. A careful 

 analysis of the distribution of plants in Ireland reveals the existence of 

 several fairly well-defined types. There is a marked tendenc}' to a 

 "central" or " marginal " distribution, the result of the configuration of 

 the country, the central group being largely composed of lowland, cal- 

 cicole, and aquatic or paludal species ; the marginal of calcifuge, upland, 

 and dry-soil plants. Well-marked northern and southern, eastern and 

 western groups also exist, the boundaries between them consisting of 

 lines running not exactly east and west, or north and south, but rather 

 north-north-eastward from Cork to Londonderry, and east-north-east- 

 ward from Galway Ba}- to Dundalk Bay. For these six types of distri- 

 bution the author proposes the names Central, Marginal, Ultonian, 

 Mumoniau, Lagenian, Connaciau, the last four being taken from the old 

 names of the four provinces of Ireland, in each of which one of the 

 groups attained its maximum. The characters of each plant group aud 

 its relations to the climatological and physiographic features of the 

 country were pointed out. 



THK CORK VALLEYS. 



BY J. PORTER, B.E. 



The author discussed the special features which were presented by the 

 drainage system of Cork County, including the abrupt change of course 

 which transfers each of the trunk rivers of the east from one longitudinal 

 strath to a more southerly one, and the more or less straight and 

 meridional character to the cross-courses The paper connected the 

 abrupt changes from one main strath to another with glacial inter- 

 ference, while it assigned to faulting and the rapid flow of the preglacial 

 streams conjointly the determining part in bringing about the meridional 

 character of the cross-courses and many of the tributary glens. 



