ELEMENTS OF BOTANY. xvii 
106. The preceding considerations refer solely to Phenogamous Plants, or 
those which bear flowers, consisting of stamens and pistils, and produce seeds, 
which contain an embryo, or a rudiment of a future plant. 
107. But there are plants of a lower grade, which do not bear flowers furnished 
with ordinary stamens and pistils, nor seeds containing an embryo, but in place 
of seeds they produce minute powdery bodies, called Spores. "These are termed 
11. .Cryptogamous or Flowerless Plants. 
108. The stems of the higher orders of Cryptogamous Plants — and these only 
are embraced in this work — exhibit nearly the same anatomical structure as 
those of Phienogamous Plants. But they grow only from the apex, without any 
perceptible increase of diameter, and therefore are termed Acrogens or Point- 
109. The different orders presenting no common type, the habit, the mode of 
inflorescence, and the process of fertilization, so far as it is known, being different 
in all of them, the characteristics of each are more conveniently explained ir. the 
body of the work, and need not be enumerated here. 
12. Classification. 
110. Classification consists in the arranging of plants possessing like structure, 
habits, &c., into groups, designating them by proper names, and defining them 
by appropriate characters. 
111. An assemblage of individuals. which are so —— inicio 
their descent from a common parent, and which preserve their characteristics 
ted from seed, is termed a Species. But circumstances connected 
with the growth of an individual may produce some deviation from its ordinary 
- state, and it then becomes a Variety. 
112. When the pistil of one species is fertilized by the pollen of another allied 
species, the result is a Hybrid. 
113. An assemblage of species agreeing with one another in structure and ap- 
pearance constitutes a Genus. In the same manner, although with fewer points 
of agreement, genera are collected into Orders, or Families, and these, in turn, into 
Classes. : 
114. But each of these may include members that agree in some important 
ints, which are not common to the others. Of such are formed the intermedi- 
‘ate divisions of Subgenera, Suborders, and Subclasses. 
115. There are two modes or systems of classification; the Artificial — 
of Linnzus, and the Natural System of Jussieu. 
116. In the Artificial System, the Classes and Orders are founded on the num- 
ber, position, and connection of the stamens and pistils, regardless of any other 
relationship. In the Natural System, every part of the plant is taken into consid- 
eration ; and the Orders embrace those genera which agree with each other in the 
- greatest number of important particulars. The Mem i is sen alan 
NUMERI DUM ora i 
