132 
The Fern Garden . 
The true ferns may be traced through many grada- 
tions of physiological structure with comparatively 
little trouble. At all events when the botanists have 
classified them, it needs no subtlety of perception to 
determine that the adder’s tongue and moonwort ferns 
are the lowest in the scale, and that their very exist- 
ence is suggestive of a gradation of similar forms late- 
rally or vertically separated from them to which these 
!east fern-like ferns serve as connecting links. The 
plants that are closest allied to the ferns are the Lyco- 
podiums, the Selaginellas, the Pepperworts, the Horse- 
tails, and the Mosses. After these we get amongst 
lichens and fungi, and as we must stop somewhere, 
the foregoing five families are all we shall recognise for 
the purposes of this chapter. Each family contributes 
beautiful plants adapted for the fern garden, and as for 
the selaginellas they are all beautiful, and we make 
selections from amongst them, because usually we 
cannot find room for the fifty or more species and 
varieties known to cultivators. 
Lycopodiums and Selaginellas closely resemble 
mosses in their branches and leaves, while in many of 
their general characters and aspects they bear close 
resemblances to ferns. They are, however, distinct 
from either, and are especially characterised by the 
nature of their leaves and their fructification. There is 
one broad distinction between lycopodiums and sela- 
ginellas, which the beginner may bear in mind with 
advantage. Lycopodiums have imbricated leaves all of 
the same shape spirally arranged. Selaginellas have 
leaves of two sizes and slightly diffei'ing in form. You 
