MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 



227 



The results of observations upon etiolated seedlings appear to 

 offer another phase of the question however. Both Sachs '*' and Noll '"' 



Fig. 166. Etiolated stems of Apios, and Bo-vieci. 



record that the stems of seedlings are capable of winding around 

 supports even when fully etiolated. Noll grew seedlings of Polyg- 

 onum Fagopyrum, Tropaeoluni majus and Brassica JVapus in a 

 dark chamber under conditions that seemed to exclude all vitiation 

 from the effects of light, obtaining marked circumnutations in half of 

 the number of seedlings in some series of tests. The period of a 

 single revolution of the growing tips ranged from eleven and a one- 

 quarter hours to two hours. The stems of the seedlings of Tro- 

 ■paeoUun and Fagopyrum, and in few instances those of Brassica also 



'^^Sachs. Vorlesungen ueber Pflanzenphjsiologie. p. 668. 1SS2. 

 i^'Noll. Ueber rotirende Nutation an etiolirten Keimpflanzen. Bot. Zeitung, 43 : 

 664. 1885. 



