Dr, Lindley’s Natural System of Botany. 295. 
ley, the Equisetacex,) and the Rhizanthe, as originally established 
by Blume, being here admitted to the rank of independent classes. 
Their claim to this rank, however, can as yet be hardly considered 
as fully established. 
“One of the first things that strikes an enquirer into the structure 
of plants, is the singular fact, that while all species are capable of 
propagating their race, the mode in which this important function is 
accomplished is essentially different in different cases. The great 
mass of plants produce flowers which are succeeded by fruits, con- 
taining seed, which is shed or scattered abroad, and grows into new 
individuals. But in Ferns, Mosses, Mushrooms, and the like, nei- 
ther flowers, nor seeds properly so called, can be detected ; but pro- 
pagation is effected by the dispersion of grains or spores which are 
usually generated in the substance of the plant, and seem to have 
little analogy with true seeds. Hence the vegetable world separates 
into two distinct groups, the Flowering and the Flowerless. Upon 
examining more closely into the respective peculiarities of these 
two groups, it is found that flowering plants have sexes, while flow- 
_ erless plants have none; hence the former are called Sexual, and the 
latter Asexual. Then again the former usually possess a highly de- 
veloped system of spiral or other vessels, while the latter are either 
altogether destitute of them, or have them only in the highest orders, 
and then in a peculiar state: for this reason flowering plants are also 
called Vascular, and flowerless Cellular. More than this, all flower- 
ing plants, when they form stems, increase by an extension of their 
ends and a distention or enlargement of their sides; but flowerless 
plants appear to form their stems simply by the addition of new 
matter to their points; for this reason while the former are princi- 
pally Exogens or Endogens, the latter are called Acrogens. Flow- 
ering plants are also for the most part furnished with respiratory or- 
gans or stomates, while flowerless plants are to a great extent desti- 
tute of them. No one then can doubt that in the vegetable king- 
dom, two most essentially distinct divisions exist, the Flowering and 
the Flowerless, and that these differ not in one circumstance only, 
but are most essentially unlike in many points both of organization 
and physiology. 
_ “Tn like manner, Flowering plants are themselves divisible into 
equally well marked groups. ‘Some of them grow by the addition 
of new woody matter to the outside of their stem beneath the bark ; 
these are Exogens: others grow by the addition of new woody mat- 
