5d AN INTRODUCTION 



and that of the second Angiospermia, of such as have 

 their seed in a vessel or pericarpium There was a 

 3d order Polypetala, expressive of such plants as have 

 many petals : This order seems to have been estab- 

 lished in favour of one genus of plants only, the Me- 

 lianthus, the flowers of which are Polypetalous, 

 though those of all the rest of this class are Mono- 

 petalous: but it is now included in the second 

 order. 



CLASS XV. TETRADYNAMIA. The two orders 

 of this class are founded on a distinction in the 

 Pericarpium. In the first order, Siliculdsot, the Peri- 

 carpium is a Silicula, little Siliqua : which differs 

 from the Siliqaa in being round, and having the apex 

 of the dissepiment, which had been the style, pro- 

 minent beyond the valves, often so far as to be equal 

 in length to the silicula. In the second order,* 8ili- 

 qucsae, the pericarpium is a Siiiqua, which is long 

 and without any remarkable extension of the style. 



CLASS XVI. MONADELPHTA. XVil. DIADEL- 

 PHIA. XVIII. POLYADELPHIA. The orders in 

 these three classes are founded on the number of the 

 stamina in each brotherhood or distinct set of stamina. 

 The titles of the orders being the same that are used 

 for the titles of the early classes of the system, the 

 explanation need not be repeated here. 



CLASS XIX. SYNGENISIA. To understand the 

 orders of this class, we must explain what is meant 

 by Polygamy in flowers. We have already treated of 

 polygamous plants, and shewn that the term Polyga- 

 mous, as there applied, alluded to the intercom- 

 munication of the male or female flowers with the 

 hermaphrodite ones, either upon the same or a distinct 

 plant ; but in respect to flowers, the term is applied, 

 to a single flower only ; for the flowers of this class be- 

 ing compound, a polygamy arises from the inter-corn* 

 munication of the several florets in one and the same 

 flower. Now the polygamy of flowers, in this sense 



