S. LEONARD BASTIN
METHUEN & CO. LTD.
36 ESSEX STREET W.C.
THE FERNS AND THEIR ALLIES
lowest forms vegetable life is a very simple affair. The
minute Algæ which clothe damp surfaces with a green film
show few indeed of the characteristics with which we are
familiar in the higher plants. Certainly they are green,
proving that the tiny cells of which they are composed
contain the wonderful colouring matter—chlorophyll, by
means of which they are able to assimilate carbon from
the carbonic acid of the air. There is, however, in
these lowly plants no sign of a stem, a leaf, or a root.
As we ascend in the scale of vegetable life we begin to
get an increasing number of distinctive characters. In
the case of the Mosses we have plants with distinct
stems and leaves. But Mosses have no true roots, neither
is there any vascular (woody) tissue in their
composition. Mounting yet higher in the scale we come to
a very important and interesting group of plants usually
referred to as the Vascular Cryptogams. In this group
are included the Ferns,................