8 4 
W. Watson. 
Few fungi and no terricolous lichens were noticed on the 
heath itself, though the former were abundant in the adjacent 
Alnus thicket, Boleti and Russulse being especially noticeable. The 
only fungus noted as occurring on the Molinia tussocks was Laccaria 
laccata, but no particular search was made for these plants. 
II. ZoNATION OF THE VEGETATION. 
The zonation of vegetation from the wet to the drier and more 
exposed positions is evident by the distribution of the vascular 
plants, but is shown in greater detail by the bryophytes. On taking 
these non-vascular plants into consideration, seven zones can be 
distinguished, and each of these, with the exception of the first, is 
characterised by the presence of a particular bryophytic species 
(Figs. 3, 4, 5). 
I. Zone of Potamogeton polygonifolitis. In the small tributaries 
or furrows where water is constantly present Potamogeton polygoni- 
folins is abundant, in fact it is the only plant evident when the water 
is more than 10 centimetres deep. Frequent examinations of the 
stream-bed showed that no vascular plant or even a characeous or 
