ClIAP. III. 



PTEROSTYLIS LONGIFOLIA. 



87 



wliich is thus temporarily imprisoned within the other- 

 wiso almost completely closed flower. The labellum 



Fig. 14. 



Ptkrostylis longifoua. (Copied from Jlr. E. D. Fitzgerald's ' Australian 

 Orchids.*) 



A, Flower in its natural state : the 



outline of the column is dimly 

 seen within. 



B. Flower with the near lateral 



petal removed, showing the 



column with its two shields, 

 and the labellum in the position 

 which it occupies after having 

 • been touched 



remains shut from haK an hour to one hour and a 

 half, and on reopening is agaia sensitive to a touch. 

 Two membranous shields project on each side of the 



