GEOLOGY 25 
in this country. The rocks at almost every geological horizon are quarried 
in great quantities for some industrial purpose and used in many parts 
of the country ; the Charnian rocks and their associated igneous rocks, 
as well as Mountsorrel granite for road metal, setts, building stone and 
slates, the coal measures for coal and fireclay, the Carboniferous lime- 
stone for lime-burning and road-dressing, the marls and clays for gypsum 
and brick-making, the Lower Lias Limestone for cement, the Middle 
Lias and Inferior Oolite ironstone and limestone for smelting, and the 
Quaternary sand and gravels for road-dressing and concrete. 
Ill. 
THE FLORA OF LEICESTERSHIRE 
CONSIDERED BOTANICALLY, AND IN RELATION TO 
HUMAN ACTIVITIES 
BY 
A. R. HORWOOD, F.L.S. 
Flora in Relation to the Geological Formations—Flora of the pre-Cambrian 
Rocks of Charnwood Forest—Flora of the older Limestones—Flora of the 
Coal Measures—Flora of the Oolites—Flora in Relation to Human Activities 
—Scenery and Vegetation—Local Plants of Economic Interest—Great 
Chalky Boulder Clay—Forestry and the Flora of the District. 
SoME OF THE LocaL Types OF NATURAL VEGETATION. 
Tue flora of Leicestershire may be considered like that of any other area, 
characterised by the nature of the soils derived from the geological 
formations of the area, each soil type supporting a different type of wood- 
land and other correlated plant community. Broadly speaking, the rocks 
of the whole district consist of four or five main types. 
(1) The pre-Cambrian Rocks of Charnwood Forest, largely of volcanic 
origin, of higher elevation than the rest of the county, mountainous on 
a small scale, and affording generally sandy or siliceous soils, bear woods 
of oak, pedunculate and sessile, oak-birch heath, or birch wood, grass 
heath, siliceous grassland, calluna heath, and heather moor. Such soils 
being largely confined to the area of Charnwood, the plant associations 
named and the component species are likewise more or less confined to 
Charnwood Forest. 
Deforested several times, Charnwood Forest was probably once part of 
a former more extensive forest, part of the Forest of Arden, stretching from 
the Avon to the Trent, and beyond to Sherwood, and eastward to Lyfield, 
