1914-15.] botanical society of edinburgh 371 



Conclusion. 



Impressive features of the Culbin Sands, as compared 

 with other dunes which the authors have visited, are : — 



1. The variety of the associations in different parts of it; 

 the marked way in which these differently composed floras 

 merge into each other ; the equally marked way in which, 

 at other points, they suddenly meet; the frequency with 

 which one passes, when moving in the same direction, 

 through a transitional series from one association to 

 another, and then through the same series reversed. 



2. The remarkable richness of species in such compara- 

 tively small and isolated localities as the dune-marshes. 1 



3. The obvious instability of the conditions. The sequences 

 and reversed sequences not only hold from place to place, 

 but in the same place from time to time. Spots a short 

 distance apart will show successive stages from the begin- 

 ning of fixation of sand to its complete covering with 

 vegetation ; they will also show the stages in the opposite 

 process, stages which suggest that at any time the process 

 goiug on at a point, whether of progression to a richer 

 flora or to complete barrenness again, may be reversed. 



We are much indebted for help in the identification of 

 the mosses to Mr. J. C. Adam. 



List of Plants noted on Culbin Sands, 

 phanerogams and vascular cryptogams. 



RanUTbCuius Flo mmula, Linn.; B. Limgua, Linn.: B. 

 repens, Linn. : Galtha palustris, Linn. 



Cardamvne praterisis, Linn. : C. hirsuta, Linn. : ErophUa 

 verna, E. Meyer: Brassica arvensis,0. Kuntze : Capsetta 

 Biursa-pastoris, Medic. 



Viola palustris, Linn.; 1". canina, Linn. 



Pol yga la vu Iga ris, Linn. 



Lychnis alba. Mill.-, L. J lolca, Linn. ; Cerastium tetron- 

 druui. Curt.: G. viscosv/m, Linn.: C. vvlgatum, Linn.; 

 Sagino procumbent. Linn.: 8. nodosa, Fenzl. 



1 Ewing remarks on the relative poverty of the Culbins in xerophytes 

 and richness in mesophytes — The Flora of the Culbin Sands, p. 11. 



