Principles of Classification . 
different parts of the seed ; and the hilum or scar by 
which the seed is attached to the seed-vessel. The pel- 
licle or epidermis adheres closely to the outside of 
some seeds ; and the a r illus or tunic is either a com- 
plete or partial covering attached to the base only, 
and surrounding the other parts more or less loosely. 
Some seeds are furnished with a. pappus, or down, which 
is chaffy, feathery, or bristly. The seeds of dandelion 
afford an example of the feathery structure. Seeds 
are also furnished with a tail, with a beak, or with wings. 
The reeeptacle, receptaculum, is the common point 
of connection of all the other parts of fructification. 
It is called the receptacle of the flower, when the calyx, 
corolla, and stamens only, are attached to it. It is de- 
nominated a proper receptacle, when only one flower 
with its fruit is inserted into it, — and common, when it 
supports many flowers. In such as are called com- 
pound, it is very distinct, as in the daisy, where it is of 
a conical form ; in others, it is convex, flat, or concave, 
and in some it is naked, hairy, scaly, or cellular, like a 
honey-comb. 
Of the Classes . 
The Linnsean system of botany includes 24 classes, 
the characters of which are derived from the number, 
situation, and proportion of the stamens. The first 
eleven classes are determined by the number of the sta- 
mens, and the names by which they are distinguished, 
derived from the Greek language, are characteristic of 
this mode of discrimination. 
The 1st class, Monandries, signifies that the plants 
