ON THE MIXED HERBAGE OF PERMANENT MEADOW. 
1229 
tendency to form “ store houses ” for the accumulation of nutritive materials in the 
shape of tubers or other dilatations of the root or stem. Although some grasses, 
e.g., Alopecurus bulbosus, have such organs, yet none of the species found on the 
plots have been observed to develop such formations, with the exception of Alopecurus 
pratensis and Bromus mollis, in which the formation of small tuberous swellings on 
the root fibres has occasionally been observed. Many grasses produce offsets, stolons, 
or runners, either below or just above the surface of the ground, by means of which 
they are enabled to establish possession of an extended area. The stems or culms of 
the grasses are usually erect and hollow, frequently tufted, and occasionally branched 
at the base, as in the case of the species which “ tiller,” such branches being of 
essentially the same character as the creeping shoots or stolons just referred to, but 
differing mainly by their erect direction and in their office. 
“ Adventitious ” roots spring from the base of the culms in many cases, and are 
produced in abundance from the nodes or joints of the creeping shoots, especially under 
the influence of moisture. 
The blade of the leaf differs considerably in form and dimensions in various grasses, 
and also according to season and conditions of manuring. The amount and character 
of the pubescence also varies according to locality and moisture, and, in a less degree, 
according to manure. For our purpose it may suffice to mention Dactylis glomerata 
as the type of the broad-leaved, and Festuca ovina of the narrow-leaved species. 
The internal structure of the leaves, as elsewhere mentioned, though on the same 
general plan, varies in different species of the same genus, and even in the same 
species, according to locality and other circumstances. 
It would be out of place to enter here into those details as to the conformation of 
particular plants which may be found in any text-book of descriptive botany. In the 
following sub-sections relating to the individual species, attention will be confined to 
those points of structure which appear to have more or less direct relation to the 
varying external conditions of season, soil, manuring, &c., to which the plants thus 
growing in association are subjected. Such structural characteristics are only treated 
of very generally in botanical works. They have, however, been made the subject of 
special observation at Rothamsted, and the more important points will be noted under 
th’e head of each plant. In like manner those physiological endowments and life- 
habits which appear to be of more or less importance to the plant in its struggle with 
its associates will be briefly alluded to, whilst others whose bearing on the subject is 
less obvious will be passed over.* 
Anthoxanthmn odoratum. 
This fragrant perennial grass has fine, much branched, dense root fibres, forming a 
dense mat close to the surface, but not deeply penetrating. Its culms are tufted, 
erect, never creeping, 1 to 2 feet in height, and they bear flat, narrow, and ascending 
leaves. It begins to grow very early in spring and again soon after cutting, though it 
* As- to the fertilisation of grasses, see footnote at p. 1220. 
7 s 
MDCCCLXXXII. 
