92 SWARZ ON THE GENERA OF ORCHIDE^, 



each founder of a system has pursued a different 

 method. 



Tournefort was the first who undertook this 

 task; it was not, however, from the peculiar 

 figure or internal structure of the flower, but from 

 the habit of the whole plant, that he constructed 

 the generic characters of his Nidus avis, Limodo- 

 rum, Ophrys, Orchis, Helleborine, and Calceolus. 

 Ray, Rivinus, and Boerhaave followed him in 

 this. C. Knaut and Kramer took their charac- 

 ters (though not with great fuccess) from the spur 

 and other external parts, and partly even from the 

 root. Wedel gave six petal-like leaflets to the 

 flowers of Orchideae ; three of which he termed 

 the calyx, and distinguished his genera by the 

 difference of the lip. Ludwig defined them (as 

 did also Haller at first") by the form of the root. 

 Micheli also made use of this part for the form- 

 ing of some genera of this natural order. 



Linnaeus, endeavouring to extract better cha- 

 racters than thofe given by his predecessors, 

 distinguished the plants of his twentieth class 

 (Gynandria) from the others, by their male parts 



