AND THEIR SYSTEMATICAL ARRANGEMENT. 93 



being situated upon the style, or upon an elongated 

 receptacle analogous to it, bearing both pistil and 

 stamens. All the genera of the first order (to 

 which his Orchidece belong) were required to be 

 diandrous. The essential characters of the different 

 genera he borrowed from the external parts of the 

 flower, partly from the Labium ncctarii (or necta- 

 rium, as he sometimes calls it), and partly from the 

 spurs, when present. These characters appeared 

 for the first time in the Genera plantarum ; in a 

 subsequent edition he still retains them, and in the 

 fifth changes a part, and gives up some genera, 

 the species of which he transfers to others, and 

 finally establishes the characters of Orchidcaj as 

 follows : Filamenta semper duo brevissima ; stylus 

 vix distinctus ; antherce bincc nuda tunica carentes ', 

 cellulis tecta qua deorsum apcriwitur, &c. Fur- 

 ther experience has shewn how uncertain and 

 insufficient this was. 



While these improvements, or rather changes, 

 were making, Haller, by his assiduous exami- 

 nation of more than fifty species of Orchidece 

 growing wild, was enabled to propose characters. 



