( 124 ) 



VI. 



THE VEGETATION OF TEE DISTRICT LYITO SOUTH OF 



DrBLIN. 



By GEORGE H. PETHYBRIDGE, Ph.D., B.Sc, and 

 ROBERT LLOYD PRAEGER, B.E., M.R.LA. 



[Plates VIL-XIL] 



[Read May 22. Ordered for Publication May 24. Published December 2, 1905.] 



CONTENTS. 



1. Introduction and Literature, .. .. .. ., .. 124 



2. Geology and Physiography, . . . . . . . . . . . . 133 



3. Floristic Notes, .. .. .. .. .. .. .. .. 136 



4. The Methods or Survey, .. .. .. .. .. .. .. 138 



5. The Zones of Vegetation, .. .. .. .. .. .. ..143 



The Littoral Zone, . . . . . . . . . . . . . 145 



The Sand-dune Association, . . , . . . . . . , 145 



The Salt-marsh Association, . . . . . . . . . . 146 



The Rock and ClifP Association, . . . . . . . . . . 146 



The Agrarian Zone, . . . . . . . . . . . . . . 147 



The Farm-land, 147 



The Ulex europaeus Association ,. . .. .. .. ..150 



The Zone of Hill-pasture, .. .. .. .. .. .. 153 



The TJlex Gallii Association, . . . . . . . . . . 153 



The Pteris Association, . . . . . . . . . . . . 155 



The Nardus Association, .. .. .. .. .. .. 157 



The Moorland Zone, 158 



The Calluna Association, . . . . . . . . . . . . 158 



The Vaccinium Association, .. .. .. .. .. 162 



The Scirpus Association, . . . . . . . . . , . . 162 



The Eriophorum Association, .. .. .. ., ..166 



The Racomitrium Association, . . . . . . . . . . 167 



The Juncus Associations, . . . . . . . . . . . . 170 



The Woodlands, 173 



6. Notes on the Map, .. .. .. .. .. .. .. .. 176 



INTRODIJCTION. 



The distribution of the plants in any given area may be worked out 

 in two different ways. The first method, and the one whieh has until 

 recently been that chiefly adopted in this and otlier countries, is 

 essentially an analytical one. It consists in making as complete a list 



