Pethybkidge & Praeger — Vegetation South of Dublin. 169 



mentioned above, the ground is very uneven, so that walking over it 

 is troublesome; nay, in some localities it is a case of jumping from 

 island to island, rather than walking at all. In these latter areas the 

 form of the ground is due primarily to the denuding action of the 

 weather, the softer parts of the peat being removed, and the hollows 

 thus formed becoming pools in Avhich Sphagnum and Eriophorum 

 flourish, Sci)pus finding a foothold on the margin. These pools are, 

 iu some cases, isolated, in others connected together in a complex net- 

 work. The islands of undenuded peat are clothed on their sheltered 

 sides (east) with stunted Ccdlima, Empetrum^ and Erica Tetralix, while 

 on their western and exposed faces Racomitrium loves to disport 

 itself. 



In some cases, however, the unevenness of the ground is due to 

 the growth of the bosses of Racomitrium itself. As before, Calluna, 

 Empetrum, and E. Tetralix flourish in the shelter of the east sides of 

 these bosses, w^hile the growing part of the Racomitrium spreads its 

 face westwards. Hence it comes about that the Racomitrium moor 

 presents two rather different aspects, according as to whether one 

 looks at it from the east or from the west. As will be apparent from 

 the photograph reproduced herewith, on looking at the association 

 from the west, the Racomitrium bosses are very conspicuous. 



The composition of this varying and, perhaps, too artificial 

 association, in its wet forms, will be seen from the following 

 compiled analysis : — 



CoilPOSITION OF THE EACOMITRirM AsSOCIATlOX. 



Numher of stations examined — eight. 



Callu^ta vulgaris. 8. 

 scirpus c^spitosus. 8. 



RACOillTRTDM LANUGIXO- 



SUM. 8. 

 EuiOPHORUM ANGrSTIFO- 



LITJM. 8. 



Empetrum nigrum. 8. 

 Sphagnum spp. 7. 

 Cladonia rangiferina. 7. 

 EmcA Tetralix. 6. 



JrXCUS SQUARROSUS. 4. 



Eriophorum vaginatum 

 Yaccinium Myrtillus. 4. 



Potentilla Tormentilla. 4. 

 !Narthecium ossifragum. 3. 



Ulex Gallii. 2. 

 Drosera rotundifolia. 

 Pinguicula vulgaris. 

 Luzula maxima. 1. 

 Carex glauca. 1. 

 C. binervis. 1. 

 Molinia caerulea. 2. 

 Nardus stricta. 1. 

 Poly trichum. 1 . 



