Vegetation of the Island of Gothland. 265 
physical conditions of the habitat, especially the calcareous and 
alkaline character of the water. Very large tracts of country 
bearing similar vegetation formerly existed and still bear the name 
of “ myr,” but the fens are now rapidly disappearing. In some 
places the drainage dykes show peat to a depth of 4 feet or more, 
resting on a bed of marl, but detailed observations on this point are 
wanting. The Cladium fens have, by drainage, been turned into 
rank pasture for cattle and the widespread use of this plant for 
thatching cottages has practically died out. 
Calcareous Bog. 
While the fen vegetation, as just described, is so like that of our 
English fens, it passes over into a type of calcareous bog which is 
quite unknown in East Anglia, though similar to a type occurring 
in the North of England. One of the most characteristic plants of 
this association is Primula farinosa, which often forms a pure open 
association. The closed vegetation of this type contains abundant 
Sclicenus nigricans (or ferrugineus) and Eriophorum tali folium, while 
the following plants are very common :— 
Tofieldia calyculata. Orchis incarnata. 
Epipactis palustris. Juncus obtusijlorus. 
Sesleria ccerulea. Drosera longifolia. 
Pinguicula vulgaris. 
No critical observations on the nature of the soil could be made, 
but from casual inspection it appeared to be much more calcareous 
and less peaty than that of the fen. Two cases were noticed where 
one shore of a lake had vegetation of the Phragmites-Cladium fen 
type, while the opposite shore had vegetation of the limestone bog 
type. One of these was Tingstade trask. The northern shore is 
bounded by a flat of soft grey mud which was being colonised by 
Sclicenus ferrugineus. Further away from the water Drosera and 
Eriophorum were very abundant, the vegetation being still of the 
open type. This passed gradually into closed turf-like vegetation, 
which would scarcely ever be submerged except in the wettest 
seasons. In this turf the species mentioned above were very frequent, 
while several small bushes of Juniperus, Rhamnus Frangula and 
Salix sp. occurred. In places where lakes had been drained the 
pine forest seemed to be quickly advancing over their margins. 
Seedlings of Pines and Juniper were springing up in great numbers 
in some of these localities (PI. V, fig. 2). 
It might be suggested that we have here two parallel develop- 
