360 MR. T. W. WOODHEAD ON THE 
Bracken, therefore, gives us a very good outline of these slopes 
of the moorland valleys and cloughs, and up these it ascends to a 
height of 1700 feet. (Fig. 10, p. 353.) 
To the east it descends along the valley-slopes in broken 
strands to spread out in sheets on the plains when protected by 
trees, to be again cut out by the deep shade of Sycamore, Elm, 
and Beech. 
The woodlands of the hill-slopes consist ehiefly of Oak, Birch, 
and Pine. All are planted, but are often on the sites of 
primitive forest or scrub, and none of the woods in this or the 
two other zones considered is now primitive. They are given up 
rather to the preservation of game than to the growth of timber. 
Not much felling or pruning is done, and thus they remain 
practically undisturbed for long periods. The Oak ascends to 
1200 feet, but dies out above that limit, and the undergrowth is 
essentially that of the adjacent moorlands. In the neighbour- 
hood of Harden Moss are Pine-plantations from 1500-1100 feet, 
and again at Black Moor from 1000-800 feet; but here they are 
fully exposed to the prevailing winds, thrive badly, and in 
several areas all the trees are dead. The undergrowth is 
chiefly Bilberry (Vaccinium Myrtillus). 
(b) Heather Zone of the Millstone-Grit Plateau. 
The central portion of the district is sharply marked off from 
the western, and consists of a magnificent Millstone-Grit plateau, 
through which deep narrow valleys have been cut into the shales 
below by the tributaries of the river Holme. Though now 
highly cultivated, it was formerly a heather moorland, and the 
several portions are known as Thickhollins Moor, Melthan Moor, 
Black Moor, Honley Moor, Netherton Moor, and Crosland 
Moor. This plateau dips gently to the S.E. from 1000 to 
450 feet. The soils are shallow, sandy, well drained, and in 
places covered with a thin deposit of peat usually not more than 
6-12 in. deep. In contrast to the Moss Moor, the conditions 
here are such as to be unfavourable to the formation of deep 
ill-drained peat. Some of this, as at Honley Woods, is Bracken 
peat, being composed almost entirely of the remains of this 
plant, and though this species is still present and in places 
abundant, the Ling and Heath associates are now dominant. 
This area is swept by the prevailing west winds, and in the 
spring by the dry east winds, which, together with the soil- 
