275A The Romance of Wild Flowers 
oils in glands of the leaf. Other distinguishing 
characters will be found in the square stems and the 
opposite leaves. 
We have no less than seven species with several 
sub-species of Mint (Mentha) in this country, and 
these, from their variability, are not always identified 
without difficulty. They are all distinguished by 
their strong odours, which have the effect of protecting 
them from being eaten by most plant-feeders, to whom 
the aroma is objectionable. This in truth .is the 
reason why these plants have taken to develop the 
essential oils which the perfumer finds so valuable. 
The flowers in all the Mints are almost regular, some- 
what bell-shaped and small, four-lobed, though the 
calyx is five-toothed. The upper lobes are broader 
than the lower, and it is probable that this marks a 
falling off or degeneration from a condition when the 
flower was larger and distinctly two-lipped, like its 
related Labiates. There are four stamens, distant 
from each other, and the style is not central. 
One reason for supposing they have degenerated 
may be found in the fact that they produce few 
healthy seeds, the rootstock having taken to branch 
out and run freely beneath the surface. This habit 
of increasing by stolons may have led to the decrease 
in the size and showiness of the flowers, the plant 
having become to a certain extent independent of 
them for perpetuation. With the exception of the 
Corn-mint (IZ. arvensis), they are all plants of wet 
places, such as the margins of ponds, riversides, 
and marshes. This exceptional species may be found 
in cultivated ground and drier wastes, and bears two 
forms of flowers—small ones, in which only the style 
