Chaf. IV] TROPICAL DISTRICTS CONSTANTLY MOIST 333 



with justice, included it among the protective devices. Opinions however 

 differ as to the nature of the danger to be guarded against. Wiesner 



Fig. 175. Brownea hybrida with pendent young twigs. Botanic garden at Buitenzorg. 

 From a photograph by M. Treub. 



considers the danger to be too strong illumination ; Potter, too great heat ; 

 Stahl, mechanical damage by heavy rain ; Haberlandt, several factors 

 acting simultaneously. Decisive experiments have not yet been made. 



