1218 
MESSRS. J. B. LAWES, J. H. GILBERT, AKD M. T. MASTERS, 
a relatively short distance, at a greater or less angle on, or slightly beneath, the surface 
of the soil; 2. As dilated and tuberous ; 3. As contracted and tufted, as in many of 
the grasses, whose tufts or “hummocks” consist of the short contracted stocks emitting 
plentiful root-fibres below, and dense tufts of leaves above ; 4. As creeping; as in the 
case of Twitch or Bent ( Triticum repens), where the stock gives off slender creeping 
branches on or beneath the surface, such branches sometimes having the power of 
rooting freely at the nodes, as in Twitch; at others not rooting freely, as in the 
stolons, or offshoots of Achillea Millefolium* In any case they are usually termi¬ 
nated by a bud or cluster of leaves, surrounding a “ growing point,” and which is 
capable of rooting and forming a distinct plant. 
Stem. Under this head we may include all those organs whose office it is to bear 
well-developed leaves and flowers. It is not necessary to discuss the many forms the 
stem may assume. It will suffice to recall that some plants have but a single stem 
springing from the root-stock, while, in other cases, as in many grasses, the stems or 
culms are numerous and tufted. Of course, if the root-stock branches there will be 
stems corresponding to those branches. The number of the stems and of their branches, 
their habit, their direction, whether erect or decumbent, their texture—all have an 
important influence on the terms of competition between different plants. The pro¬ 
duction of numerous stems, as in those grasses which “ tiller,” seems connected with the 
necessity for securing sufficient nutriment from the air, solar light, &c., in a short space 
of time. 
Leaves. —On ordinary meadow land a great variety in the shape, size, and direction 
of leaves, as well as in the mode in which they are packed in the bud, may at once be 
seen. There are the grasses with their long, thin, narrow, folded or convolute leaves, 
at first more or less erect, afterwards, according to their position on the stem or culm, 
spreading. There are the Plantains and Clovers, with their broad, flat leaves ; there 
is the Daisy, with its spoon-shaped leaves pressed flat to the soil; and between these 
extremes every conceivable variation in size, shape, and direction occurs. These varia¬ 
tions are, it is to be supposed, sometimes associated with corresponding differences in 
internal structure, and more especially with diverse functional endowments, as a result 
of which the life-history of the plants presents the differences which are so obvious, 
but the explanation of which is at present so incomplete. 
The influence that the mere shape and direction of leaves may have upon the 
struggle between different plants is strikingly illustrated in early spring, before they 
have started into growth. At that time, many of the “ weeds ” of grass-land have the 
form of flat rosettes, resting immediately on the surface of which they occupy circular 
patches of considerable area. Such is the case in the Plantain, in the Dandelion, in 
the Hawkweed, in the Daisy, and many others. Now, if these plants start into 
* A note of Mr. Darwin’s may be quoted bere as showing the beneficial effects of cross fertilisation on 
Origanum vulgare : —“The superiority of the crossed plants was truly wonderful, owing to their increase by 
stolons.”—(‘ Fertilisation of Flowers,’ p. 96.) 
