SYSTEMS OF FLOWERING PLANTS 51 



the existence of sexes in plants than anybody else, and 

 that the physiological importance of stamens and styles 

 was a proof of their systematic value. Neither of these 

 beliefs can stand inquiry, but both were extremely influ- 

 ential on contemporary opinion. The so-called Sexual 

 System achieved an immense success everywhere but in 

 France and Germany. Botanists of small experience 

 were now able to say whether the plants which seemed 

 to be new were really undescribed or not ; if undescribed, 

 what was their appropriate place in the system. The 

 congestion of systematic botany was relieved. 



The great naturalist appealed to posterity by publish- 

 ing the sketch of a natural system of flowering plants, 

 which he accompanied by judicious expositions of the 

 philosophy of classification. He had the permanent 

 reform of systematic botany really at heart ; he did not 

 believe that his own Sexual System could be final ; and 

 he was glad to help in setting up a better one. To this 

 end he united groups of genera into families which he 

 did not pretend to define, being often guided only by an 

 obscure sense of natural bonds of union. Bernard de 

 Jussieu, one of the most patient and observant of sys- 

 tematists, devoted his life to the same task, and profited 

 by the example of Linnaeus. He published nothing, but 

 found expression for his views in the arrangement of a 

 botanic garden at Versailles. His ideas were after- 

 wards developed by his nephew, A. L. de Jussieu, in 

 the Genera Plantarum (1789). 



Affinity became at length the avowed basis of every 

 botanical system. No convenience in practice, no 

 agreement or difference in habit, was knowingly per- 

 mitted to override this mysterious property. What 

 then is affinity ? What are natural groups of animals 

 and plants, and how do they arise ? Until the year 



