ON THE MIXED HERBAGE OF PERMANENT MEADOW. 
1219 
growth earlier than the neighbouring grasses they will necessarily have an advantage 
over them, and will more or less crowd them out. If on the contrary the grasses 
begin to grow first, or the growth of the broad-appressed leaved plants be checked, 
then the grasses, or other plants, will get the start and overpower the rest.* In other 
cases, the flat leaves closely pressed against the soil prevent the growth of other 
plants ; for instance, on an ill-kept lawn, the Daisies increase partly by virtue of their 
much divided stock, partly by their flat leaves closely pressed to the soil, and prevent¬ 
ing the growth of other plants. In the Buttercups the leaves, which in early spring 
form a rosette appressed to the ground, become speedily lifted from it by the elongating 
leaf-stalks, and room is thereby left for the encroachments of the-grasses or other 
plants which may be in the neighbourhood. In plants like Conopodium denudatum , 
the leaf in its initial stage is packed into very small compass, almost like a furled flag. 
In this state it is thrust up amid other leaves till it gets space to unfold. In other 
cases, as in the clovers, the two halves of the young leaves are folded like a sheet of 
note-paper and remain so till by the lengthening of the stalks they grow beyond 
the obstruction. In the Festuca ovina the thin, slender, cylindrical leaves easily make 
their way amongst the surrounding foliage, and this may be one reason for the pre¬ 
dominance of the plant, while its comparatively small evaporating surface may also 
stand it in good stead. In fine, there are endless adaptations such as those cited, 
well known to the botanist, and familiar to the most superficial observer of plants. 
It is not needful to dwell upon them here at any greater length, our object being 
not to call attention to special arrangements, but to the general fact that all these 
variations, in the growth and “ habit ” of plants, are elements to be considered in 
studying the nature and the force of the struggle for existence among them, and the 
circumstances that determine the “survival of the fittest.” 
With reference to the minute anatomical structure of the leaves and herbaceous 
parts of plants, it is well known that external conditions have no inconsiderable 
influence upon them. The structure of aquatic plants is a case in point; the anatomi¬ 
cal construction being profoundly modified as a consequence of the medium in which 
the plants grow. So, also, the increased succulence—due to augmented size or number 
of cells—seen in plants grown by the sea-side is matter of common observation. The 
densely woody contracted habit of shrubby plants growing on the higher mountains has 
also often been noted. Amongst the most recent investigations on this subject are those 
of M. Duval J ouve, who has examined the structure of the leaves of grasses as modified 
* In the spring of 1875 one of ns was a witness of a struggle of this kind between Cerastium triviale 
and Plantago Icmceolata. The frosts of March had very severely injured the outermost leaves of the 
Plantain, a large number of which were growing on an exposed railway bank where little else grew. 
Each plant was surrounded by a growth of Cerastium triviale which was much less damaged, if at all, by 
the frost, and which consequently invaded and, to a considerable extent, overpowered the Plantain. As 
the spring went on, however, the new leaves of the Plantain, when starting into growth, assumed an 
upward direction instead of the usual horizontal one, and the plant quickly outgrew the Cerastium , and so 
regained its supremacy. 
