MR. W. A. NICHOLSON ON BOTANY OF SUTTON. 285 
approximation, as the operation of counting plants under 
such conditions is more difficult than one would be led to 
suppose. We may compare this with a census made by 
Mr. Wallis,* of a square yard of rather bare chalky soil in 
the Cambridge District, which was as follows : — 
125 Plants of Festuca ovina. 
40 Leontodon hispidus. 
8 Hieracium Pilosella. 
3 Gentiana campestris. 
2 Polygala calcarea. 
2 A vena pratensis, seedlings. 
It will be noted that though there appears to be a greater 
number of plants in the latter locality, all of a distinctly 
xerophytic type, the number of species is less than half that 
of the square yard of marsh. The comparison seems to show 
the more monotonous character of a strictly xerophytic 
flora. The square yard of marsh examined formed part of 
a bog which was evidently submerged, during some months 
of the year, under an inch or two of water. In the same 
marsh, but outside the square yard examined, were plants of 
Epipactis palustris, Crantz. 
Orchis latifolia, L. 
Myrica Gale, L. 
Salix repens, L. 
ScHCENUS NIGRICANS, L. 
Cladium jamaicense, Crantz. 
The surface of the marsh was broken here and there by 
dense clumps of Salix and Myrica Gale. These clumps 
afforded shelter to bright masses of Spir&a Ulmaria, L., 
Lysimachia vulgaris, L., Lythrum Salicaria, L. and the more 
sombre-coloured Valeriana officinalis, L. 
A more varied flora was exhibited in a marsh meadow on 
the Sutton village side of the Laboratory. I venture to use 
the term marsh-meadow to signify an intermediate position 
between actual marsh and meadow. Though rather wet in 
# See ‘ Flora of Cambridge District,’ A. Wallis, B.A., p. 224. 
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