
12 THE BRITISH FERNS. 
have been resorted to as affording generic or specific distinctions ; 
but for this purpose they have little value, for they are variable both 
in number and arrangement in plants of the same species of different 
degrees of vigour, as well as at different elevations of the same 
stipes. The system of vessels is further carried through the frond, 
in the ribs and veins which traverse the various leafy parts into 
which it is divided. It is this connection of the veins of the fronds 
with the entire vascular system, and the fact that it is on some part 
of these veins that the spore cases are borne, which gives to venation 
its value in the systematical arrangement of these plants. 
The Fronds of Ferns are the leaf-like organs which are borne on 
the proper stem. The leaf-like character they bear, has led some 
botanists to consider them as true leaves, and to reject the term 
frond altogether. This term—frond, has however long been, and 
still is commonly used for that part in the Fern which occupies the 
place of the leaf in flowering plants, and it is conveniently retained 
to express the fact that these two organs are not quite identical in 
character. The frond of the Fern differs from the leaf of the: 
flowering plant in this, that it actually bears on its surface the parts 
known as the fructification, which the true leaf does not. This is 
the popular view. In an exact physiological sense, perhaps, this 
difference does not exist, inasmuch as the so-called fructification of 
Ferns is not strictly analogous to the fructification of flowering 
plants, but is rather to be considered as analogous -to the little 
buds or bulbils which some plants throw out from their surface. 
The peculiar manner in which the reproductive parts are borne on 
this portion of the plant may, however, be taken to indicate an 
essential difference, or at least to show that the frond is something 
more than the leaf. An analogy has been traced between the fronds 
of Ferns and the deciduous branches of other plants; but neither 
are they, properly, branches, and the analogy does not hold good, 
because, though fronds are sometimes articulated with the stem, 


