THE NATURAL HISTORY OF BRITISH GRASSES. 67 
less prevalent on the chalk range, and the quantity of lime 
which its ash contains may have something to do with this 
preference. The per centage of this product (lime) in B. 
erectus, when compared with some other species, is interest- 
ing: we therefore copy it from Mr. Way’s Fourth Report 
on the Analyses of the Ashes of Plants :— 
Per centage of 
Lime in Ash. 
Festuca duriuscula (a common chalk species)... .. 10°31 
Bromus erectus (upright brome) .. «- .. .. 10°38 
Dactylis glomerata (cocksfoot) .. .. .. .. .. 5°82 
Alopecurus pratensis (meadow foxtail) .. .. .. 3:90 
Indeed as regards lime, out of sixteen species the B. erectus 
is only exceeded by the following :— 
Per centage of Lime, 
Poa annua (annual meadow) .. .. .- .. .. 11°69 
Phileum pratense (Timothy grass) .. .. .. «. 14:94 
—the first of these always succeeding best on road-scrapings 
from limestone road-metal, as Bristol limestone, and the 
latter on alluvial mud-banks from rivers, which is always 
full of shells. These are facts which, while they show the 
general correctness of Mr. Way’s analyses, at the same time 
point out their value and importance. 
The B. erectus is usually refused by cattle; it is a tall 
grass, but from growing few culms and long leaves it ap- 
pears much more productive than it really is. Whatever 
tends to the improvement of the pasture contributes to its 
disappearance, and its presence in quantity may be held as 
a sure sign of poverty of soil, as well as an evidence of its 
calcareous nature. 
Avena—panicle more or less lax; glwmes thin and 
membranaceous; glwmels pointed, adherent to the 
seed. 
In this genus we have two divisions, one of which con- 
tains strictly agrarian species, which are doubtful natives, 
and are perhaps only derived from degenerated corn-oats. 
The other contains very distinct plants, exclusively belong- 
ing to the meadow. 
FE 
