Introduction. 
XXXI 
In the selection of specimens for the herbarium some care is required, as it is important 
that each plant, so far as possible, should be represented in all its parts and in its various 
stages. Of the smaller ferns, such as the Aspleniums, Moonvvorts, Adder’s-tongue, and the 
like, the whole plant should be shown ; by this means it will, in many cases, be easy to 
secure upon one and the same specimen fronds in different stages of growth, some being 
arranged so as to show the upper and others the under surface, the mature fructification 
being always represented. Of larger species, such as the Male Fern, it will not be possible 
to take the whole plant ; here a couple of representative and fully-developed fronds, showing 
the upper and under sides, must suffice. It will be impossible to show even a single entire 
frond of such ferns as the Bracken or Flowering Fern ; a pair of pinnae with the apex, or, 
in the latter case, the fertile portion of the frond, will however give a fair idea of the plant. 
Variations in the size and form of ferns, however caused, may well be represented in the 
herbarium ; the common Hart’s-tongue, for example, is strikingly different when it puts forth 
small, stunted, but mature fronds from the crevices of an old stone wall, from the same fern 
when it sends out long bright green fronds from some shady hedge-bank, or from the mossy 
border of some old well. Most ferns growing on or rather in walls are reduced to their very 
smallest proportions under such unfavourable circumstances ; indeed, it is often a marvel how 
they manage to exist at all in a position so unsuitable to their full development. Then we 
often find, as in the Hart’s-tongue, curiously curled, or forked, or variously divided fronds, 
some of which become permanent, and are reproduced from spores ; or variations in the 
toothing of the margins, such as are noticeable in some of the more striking forms of the 
common Polypody ; these, too, must find a place in our collection, which will in this manner 
be made very instructive, and far more interesting than would be the case were we content 
with a solitary example of the ordinary typical state of the fern. When it is possible to 
secure a seedling, or very young state of a fern, it is quite worth while to do so; in the 
Bracken, for instance, as we shall see later on, the young state is so different in appearance 
from the mature plant that it has even been described as a distinct species. But 
undeveloped and barren specimens have led to many mistakes in identification ; any one who 
has had experience in naming collections of ferns knows only too well the kind of specimens 
with which well-meaning amateurs torture their friends — the small seedlings of Male Fern 
which they attempt to transform into Cystopteris, or the immature Shield Fern, which “must 
surely be the true Holly Fern, it is so very like the pictures of that plant.” He who is wise 
will be careful before he commits himself to naming ferns of which the characteristic fructi- 
fication is not developed. “ By their fruits ye shall know them ” is a text which the 
botanist will do well to bear in mind when he is appealed to, to determine some doubtful 
flower or fern. The rhizome, or underground stem, of some species should be carefully dug 
up and represented in the herbarium — as, for example, in the case of the Marsh Fern 
( Aspidium Thclypteris ), of which the long creeping rhizome is very characteristic. 
The size of the specimens we select for our fern collection must, of course, be regulated 
by that of the paper upon which we intend to mount them. In Continental herbaria, indeed, 
plants are less frequently mounted than placed loose in a folded sheet of paper, but our 
English custom is to mount them in some way upon sheets of stiff paper. In the British 
Museum Herbarium the great fern collection is laid down upon paper measuring twenty-one inches 
by thirteen, this being an especially large size, intended to allow of a more satisfactory repre- 
sentation of the larger species than is possible when smaller sheets are used ; but it will 
generally be found that sheets sixteen inches by eleven or so are amply sufficient for all 
