C 2 INTRODUCTION. 
plants this consists of one, in others of several leaves ; 
and it is frequently tubular, as in the polyanthus, and 
cowslip. 
5. The COROLLA, or blossom, is that coloured part 
of every flower on which its beauty principally de- 
pends. The leaves that compose it are denominated 
petals. Some flowers, as the convolvolus and campa- 
nula, have only a single petal ; and others, as the rose 
and peony, have several petals. 
6. In the centre of the flower there are two kinds of 
organs on which the fructification and re-production of 
the species more particularly depend. These are the 
stamens, and the pistil. The STAMENS are slender, 
thread-like, substances, which surround the pistil. They 
each consist of a filament or thread, and an anther or 
summit : the latter contains, when ripe, a fine dust or 
powder called pollen. This, though, to the naked eye, 
it appears a fine powder, is so curiously formed, and is 
so various in different plants, as to be an interesting 
object for the microscope. Each grain of it is, com- 
monly, a membranous bag, round or angular, rough or 
smooth, which remains entire till it meets with, any 
moisture ; it then bursts and discharges a most subtile 
vapour. 
7. The PISTIL is a prominent part, immediately in 
the centre of each flower, which adheres to the fruit, 
and is destined for the reception of the pollen. Some 
flowers have only one pistil; others have two, three, 
four, &c. and others more than can be easily counted. 
8. At the foot of the pistil is situated the germen. 
This, when grown to maturity, has the name of peri- 
