362 MR. T. W. WOODHEAD ON THE 
remember. the shallow sandy nature of the soil here) in strong 
contrast to species in the same wood growing on the steep, 
moist, sheltered slopes. The trees, too, on the exposed parts 
are generally stunted, being little more than tall shrubs. 
(c) Coal-Measure Area. 
The river Holme forms a well-marked boundary between 
the Millstone-Grit plateau and the Lower Coal-Measures. The 
rocks here consist of shales, clays, and fine-grained sandstones 
often in rapid alternation. The soils offer a striking contrast to 
those of the west; they are generally deeper and consist of more 
or less clayey loam, and therefore moisture is more constant. 
The general altitude of this area ranges from 450 to 200 feet, 
though to the south-east the hills rise to 1200 feet. In parts 
(usually the higher level) the soils, where they lie immediately 
above the sandstones, are not uncommonly shallow, well-drained, 
relatively dry, and yield a flora distinctly xerophytic. It is on 
these soils that the heath-plants—Bilberry, Ling, Deschampsia, 
and others—are carried, often in small patches, to the east. In 
the days prior to high cultivation there is evidence that these 
tracts were much more extensive than at present, and yielded 
species now extinct, such as Listera cordata, R. Br., &c. While 
Oak is still the dominant tree, there is a greater development of 
Sycamore, Elm, and Beech. With the deeper soils, increased 
moisture, lower altitude, and less exposure the trees thrive better 
and attain much greater dimensions than in the higher regions 
to the west. But in both areas, though more especially to the 
east, tree-growth is handicapped by the smoke-cloud from the 
manufacturing towns and villages in the district. The under- 
growth consists largely of mesophytes, the three characteristic 
plants being Bracken (Pteris aquilina), Holcus mollis, and 
Scilla festalis, forming a Meso-pteridetum. To the south-east, 
in the neighbourhood of Cheese Gate Nab and Pike Lowe, 
however, the hills ascend to 1200 feet. They are capped with 
Grenoside Sandstone, and here, as well as on their steep and 
exposed shaly slopes, we get a repetition of the xerophytes 
noticed on the slopes to the west, viz., Vaccinium Myrtillus, 
Calluna Erica, DC., Erica cinerea, Linn., E. Tetraliv, Linn., 
Pteris, and xerophytie grasses; these plants also form the 
characteristic vegetation of the undergrowth of the woods on 
these hill-slopes. 
