NAMED, AND STUDIED. 97 
FLOWERING on PH#NOGAMOoUs Pranrts, namely, those that are propagated 
by means of real flowers, producing seeds, which contain an embryo ready formed. 
The lower series consists of 
FLOWERLESS OR CrypTécamous Pxanrs, which produce no real flowers and 
no true seeds, but only something of a simpler sort, answering to flowers and giv- 
ing rise to spores, which serve the purpose of seeds. ; 
309. This has been explained in Chapter II. Section II. p. 58. Next, the 
great series of Flowering Plants is divided into two Classes. 'These classes are 
distinguishable by the stem, the leaves, the flower, and the embryo or germ of the 
seed. They are: — : 
Class I. Exocens, or Dicorrtepons (more fully named, Exogenous or Di- 
cotyledonous Plants). Plants of this class, as to their stems, have the wood ‘all 
between a separate pith in the centre and a bark on the surface, and each year the 
stem jives, it forms a new layer of wood on the surface of that of the previous year 
(111, 115-118). As to the deaves, they are netted-veined or reticulated, the veins 
branching and forming meshes (126, 127). As to the flowers, their parts are gen- 
erally in fives or fours (or the double or treble of these numbers), very rarely 
in threes. As to the embryo, or germ, it always has a pair of cotyledons or seed- ° 
leaves (48), or sometimes more than a pair (49). 
Class II. Enpocens, or Monocoryrrepons (or more fully, Endogenous or 
Monocotyledonous Plants). Plants of this class, as to their stems, have their wood 
in threads mixed with the pith and scattered throughout every part, never forming 
layers, and the bark is never to be pecled off clean from the wood (112~—114). 
The eaves are almost always parallel-veined (127-129). The flowers have their 
parts in threes (or twice three), very rarely in twos or fours, never in fives, which 
is much the commonest number in the other class. And the embryo has but one 
cotyledon or seed-leaf (47, 50). 
310. So the class of any plant may be told from a piece of its stem alone; or 
from a single leaf, in most cases; or from a blossom; or from a seed; or from the 
plantlet as it springs from the seed, and in its first leaves shows the nature of the 
embryo. The seeds generally are not easy to study without a dissecting micro- 
scope, nor can we always have them growing. But the student will hardly ever 
fail to tell the class at once, by the stem, the leaves, or the flowers, and by the 
whole look of the plant. 
811. The first Class divides into two Subclasses, of very unequal size, viz. : — 
