XXXV1 
INTRODUCTION. 
that they have not been referred to any common type, but have to be sep¬ 
arately defined and described under each family. What are called their 
flowers and fruit are not constituted on the plan of those organs as char¬ 
acterized in the foregoing sections: they have no stamens and pistils, but 
bear organs of simpler kinds analogous to these. Their seeds do not arise 
from ovules, have no manifest integuments distinct from the nucleus, and 
contain no ready-formed embryo, nor can any particular growing point be 
detected antecedent to germination. To distinguish them from true seeds 
they are called Spores. 
228. The bodies comprised under this name are widely various, with 
little obvious agreement in any positive character, except that they all ger¬ 
minate and give rise to new plants. Some of them are masses of cellular 
tissue of considerable size, and are probably analogous to the nucleus of 
an ovule : others, like the powder of Club-mosses (p. 636). resemble pol¬ 
len, and indeed are formed in much the same manner; while those of the 
lowest and simplest plants (such as Fungi), are apparently reduced to sim¬ 
ple cells (although endowed with specific character), and obey the ordi¬ 
nary laws of cellular development (4, 5). 
229. The lower Cryptogamous Plants are humble vegetables, composed 
of cellular tissue alone, without any woody tissue or vessels. Still, the 
general type of vegetation (12-17) is displayed in their higher forms; as 
in Anophytes (p. 641), the class to which the Mosses belong. These 
grow upwards by a distinct axis, or stem, emit roots downward, and bear 
distinct leaves; excepting a few where the leaves and stem are confluent 
into a Frond (pp. 641, 678). They all produce two sorts of reproductive 
organs, which are analogous to stamens and pistils, and therefore designated 
as Staminidia and Pistillidia. 
230. In the lowest grades of plants, there is still further simplification of 
the organs of reproduction; which in many are reduced merely to spores 
formed of single cells, imbedded in the tissue or budding forth from the 
surface or extremity of other cells: while, as to vegetation, there is no 
longer any manifest distinction of organs, or, at least, no distinction into 
root, stem, and leaves. Indeed, a great part of these plants exhibit no 
lengthened axis, but incline rather to spread centrifugally in all directions 
equally, or in one plane, so as to form a Thallus or bed of vegetable 
matter; from which this class receives the name of Thallophytes. 
231. There are three principal kinds or orders of Thallophytes : one, 
living in air (either terrestrial or fixed to rocks, trees, &c.), and receiving 
moisture from the rain and dews, the Lichenes ; another living in water, 
the ALGiE (Sea-weeds, &c.) ; both furnished with chlorophyll (1, H 
though often of other hues than green), and therefore capable of assim¬ 
ilating and living (as they do) directly on air and water; while the third, the 
multifarious order of Fungi (Mushrooms, Moulds, &c.) are destitute of 
chlorophyll and accordingly of the power of proper vegetable digestion, 
and therefore live parasitically upon the juices of other plants or animals, 
or upon their decaying remains or products. 
232. Having been unable to include the Thallophytes in the following 
Flora, it is unnecessary to describe their organs here, or to define the nu¬ 
merous peculiar terms employed in characterizing them. The special terms 
used in the higher orders of Cryptogamous Plants are mostly explained in 
the character of the orders to which they respectively belong, or in the 
synopsis which follows them. 
12. Classification and Nomenclature. 
233. Living beings are presented to our view as individuals alone. 
Among these some are so essentially alike in every part that we involun¬ 
tarily apply to them the same name, or say that they are of the same 
species. Under the name of Species we assemble those individuals whicn 
