6 
GENERAL DESCRIPTION. 
parent flowers, and the arrangements of the seed (or 
spores) in seed-vessels (or spcn'e-cases) upon the leaves 
themselves. This is speaking of the Ferns only, for 
other Acrogens (called also Cryptogamic Plants), such 
as the Fungi, have, or seem to have, no leaves at all. 
These spore-cases are set in clusters called sori (in 
the singular sorus ), looking like patches of brownish 
or greenish brown dust, round or oblong or in lines, 
upon the backs or margins of the fronds ; and, as no 
flowering-plant bears such, the full-grown Fern is 
easily distinguishable. 
The spores — says Moore—‘are minute, roundish, 
angular, or oblong vesicles, consisting of two outer 
layers, or coatings, enclosing a thickish granular fluid, 
and they are very numerous and arranged without 
order within the spore-cases. They are so small and 
dust-like that, when thinly scattered over a sheet of 
paper are scarcely visible to the naked eye, though 
lying by thousands amongst the also minute emptied 
spore-cases. The colour, no less than the form of these 
spores, is variable; they are usually pale brownish or 
yellowish, but they are sometimes green, and the tints 
of brown and yellow are much varied. These organs 
differ obviously from seeds, in that they consist merely 
of a homogeneous cellular mass. In true seeds the radi¬ 
cle (or young root) and the plumule (or young shoot) 
are present in the embryo, and are developed from de¬ 
terminate points ; but Fern spores, consisting merely 
of a small vesicle of cellular tissue—a vegetable cell,* 
* Hence the name of Cryptogamic,—from crypt, or oell. 
