270 GREENE 



influence upon the important art of plant description. The 

 revolution which he at once brought about in the art of generic 

 diagnosis was perhaps the most priceless of his several strong 

 contributions to ph3'tography. In his Genera Plantarum of the 

 year 1737, every genus is so well characterized in words, that 

 plates and figures illustrating them are not needed. The group 

 which Linnccus takes for a genus is even more clearly defined 

 by his few descriptive sentences, than is a genus of Tournefort, 

 in which the defects of its description are eked out by a fine 

 quarto plate representing the type. And the reason why Lin- 

 naeus surpassed immeasurably every author who had preceded 

 him in the practice of generic diagnosis was that he had all 

 their understanding and appreciation of calyx, corolla and fruit, 

 and added to that his mastery of stamens, stigmas and styles, 

 the very names of which were unknow'n to the generations that 

 had preceded him, and hardly yet known to the most celebrated 

 of his contemporaries. In the later editions of the Genera 

 Plantarum, no improvement is to be noted in his diagnoses. 

 They were models as he gave them out at first, at least as viewed 

 from the standpoint of Linnasus's acknowledged greater master, 

 Caesalpino. They are still essentially the models of generic 

 diagnosis with all who still hold the Caesalpinian doctrine that 

 flower and fruit are to supply the only recognized data for the 

 establishment of classes and genera of plants. Even George 

 Bentham, who lived more than a century after the time of Lin- 

 nfeus, and was the supreme master of generic diagnosis that the 

 nineteenth century knew, was strictly a Linnasan in this regard ; 

 so that here, as at many another important point in the most 

 recent botany, the genius of the great Linnasus rules and directs. 

 Fellow members of the Botanical Societ}^ of Washington, if 

 this had been a meeting of our own, and not that of two other 

 learned societies in joint session with us, I should have preferred, 

 as I said at the beginning, to discuss some one of Linnasus's 

 greater books ; taking it as a text from which to set forth 

 his deeds ; his many benefactions to our science. To some it 

 will doubtless appear anomalous tliat here, not so much as the 

 briefest abstract of his various reforms in nomenclature should 

 be given ; especially since, in the minds of so many botanists 



