142 I.I.VVi:.\N ARTIFICIAL SYSTEM. 



CLASSES FOUNDED ON THE NUMBER AND PROPORTION OF 

 THE STAMENS. 



90. There are only two classes of this division, con- 

 sequently very little confusion will arise in their expla- 

 nation ; these are the fourteenth and the fifteenth. 



CLASS XIV. DIDYNAMIA. 



91. Character: The fourth class tetrandria, and 

 the present class didynamia have both four stamens ; but 

 in plants of the former class they are all equal, or of no 

 fixed deviation in length, but in the class didynamia, 

 there are always two long and two short. (F. 187.) 



This class of plants is peculiarly characterized by Linnrens, in 

 haying flowers with fonr stamens, two of which are long and two 

 short, the anthers converging, or inclining towards each other, in 

 there being but one style, and in the corolla being of an irregular 

 figure. It is not to be called a natural arrangement, thotigh it is, 

 indeed, much more natural than some of the other classes of the 

 artificial system. Linrueus himself, appears to have been fully sen- 

 sible of the few family affinities that subsist, between the plants of 

 the class didynamia. Accordingly, in his work on the natural orders, 

 he has disposed of the greater number of the didynamous plants 

 under two great natural families, which he calls verticiHattc and 

 pertonata. 



92. Division : There are two orders or subdivisions 

 of this class ; the first order called gymnospermia, and 

 the second angiospermia. These divisions are not founded, 

 like those of the preceding classes, on the pistils, but on 

 the presence or absence of the seed-vessel. 



93. Gymnospermia : This order contains those didy- 

 namous plants, which are destitute of a proper seed- 



