UNN.EAN ARTIFICIAL SYSTEM. 



119 



make a few remarks on the foundation and derivation 

 of the orders. 



ORIGIN AND DERIVATION OF THE ORDERS. 



17. The orders are the secondary divisions of the 

 Linnaean system, and are established upon different 

 principles. 



18. In the first thirteen classes, they are founded 

 on the number of the pistils in each liower, and derived 

 from two Greek words, one expressing number, and the 

 other, a pistil. 



19. The orders of the fourteenth class didynamia, 

 are taken from the situation of the seeds. 



1. Gymnospermia ; from gumnos naked, and sperma seed. 



2. Angiospermia ; from aggos a vessel, and sperma seed. 



20. The orders of the fifteenth class, tetradynamia, 

 are formed from a difference in the shape of the seed 

 vessels. 



