150 TRANSACTIONS OF THE [Suss. LXV. 
the clayey flats. Probably the excessive movement of 
water in such places causes leaching of the soil, as well 
as comparative freedom from acid humus. The short 
herbage and firm soil, in spite of its wetness, make it 
difficult to appropriately apply the term meadow to this 
type of wet pasture either on the plains or hillsides. It 
cannot be mown. It grades imperceptibly into dry pasture 
on similarly poor ground, and differs in little but the 
presence of glaucous sedges. 
Tussock (or Juncus) type of wet pastwre.— A third 
type of wet pasture is that characterised by the presence 
of taller and deeper-rooting plants, such as Juncus com- 
munis, interspersed usually as tufts among a shorter 
vegetation. These deep rooters are more or less helophytie, 
but as they penetrate into the subsoil they are indifferent 
within wide limits as to the height of the water-table, and 
may thus have associated with them, and occurring as an 
association between the tufts, surface-rooting plants of 
widely different character, from semi-aquatic to inhabitants 
of dry soil. 
Occasionally we find a closed association of Juncus and 
the like. It might therefore be argued that a meadow 
with tufts of Juncus is merely a transition, or a mixed 
association, passing over to a closed Juncus association. 
When we consider the reciprocal relationship of the grass 
type and Juncus type, it becomes apparent that a com- 
bination of the two gives the maximum vegetation on a 
given area, because they tap different layers of soil and 
are thus not entirely rivals. Owing to its growth form, 
Juncus remains in tufts instead of becoming uniformly 
intermingled, but nevertheless it seems better to regard 
the whole as a composite association, comparable to a 
wood with its undergrowth, rather than a mixture of 
associations. The varying nature of the undergrowth, 
however, lends difficulty to the description as a single 
association. 
Vegetation of Marsh-Meadow. 
The accessory plants vary greatly in the different types 
of marsh-meadow just described. (1) In the Juncus type 
they include many plants of wet heath. (2) In “poor 
