PEEFACE ix 



Being thus incomplete, care has been taken to arrange the 

 information respecting the distribution of species in such a form 

 that the present state of knowledge regarding each will be evident 

 from the context, and so that it can be added to and completed ; 

 and it is to be hoped that when the more conspicuous hiatuses have 

 been filled up, we shall have sufficient material for a scientific 

 exposition of Irish phyto-geography. With a view to facilitate 

 such studies, the present essay is accompanied by maps dealing 

 with those physical conditions of the country — petrography and 

 orography — which most effect plant-distribution within the area. 

 When supplemented by meteorological maps of Ireland, such as 

 may be found in Messrs. Bartholomew's " Physical Atlas," we 

 have displayed the main factors which influence the flora of the 

 island. It may be pointed out, however, that at present, when 

 comparing the vegetation of one portion of the country with another, 

 or studying the range of any species, the facts shown on map IV., 

 respecting the relative state of our knowledge of the flora of the 

 different parts of the country, must be steadily borne in mind. 



On two points I wish to lay particular emphasis. Firstly, the 

 body of the work cannot be understood without a knowledge of the 

 explanatory portion of the Introduction ; and secondly, " Irish 

 Topographical Botany" should not be used without reference to 

 " Cybele Hibernica," if the user wishes to possess all the informa- 

 tion which is at present available with regard to the distribution of 

 any plant in Ireland. 



E. Ll. p. 



National Library of Ireland, 

 Dublin, Mmj, 1901. 



