58 CAROLUS LINNAEUS 



and pistils were sexual organs and the only 

 really important parts of any flower. This 

 being true, it was plain to him, as it had been 

 to Vaillant, that Tournefort's classes of plants 

 established upon the corolla as the essential 

 organ were unphilosophically and untenably 

 based, and must fall. From that day Linnaeus 

 determined to work out a new system of classes 

 and orders of plants, on the basis of stamens 

 and pistils as the most important floral 

 organs. The result was 24 classes of plants 

 established upon characteristics of the stamens, 

 instead of the 22 classes of Tournefort dis- 

 tinguished by differences in the structure of 

 the corolla. The LinnaBan classes were very 

 much more easily learned than the Tourne- 

 fortian. His Class I embraced all genera of 

 plants the flowers of which have but a single 

 stamen; Class II, those which have two 

 stamens, and so on up to Class X, when other 

 considerations, still in part numerical, were 

 seized upon. Any mere beginner in botany, 

 with a plant in flower before him, could deter- 

 mine its class without even opening the book. 

 If the flower exhibited five stamens the plant 

 was sure to belong to some genus of Linnseus's 

 Class V. If the same flower showed also two 

 pistils, that indicated as unmistakably Order 2 



