Circujnnutatioii of Some Flowering Plajiis. 69 



work, but insufficient data were collected from which to gen- 

 eralize. Those obtained hav^e been incorporated with the 

 writer's later observations. The Scarlet Runner studied was a 

 seedling, the Lonicera had grown from a cut-back plant. 



A fine specimen of Lonicera bracJiypoda growing in the gar- 

 den, and having no chance to climb, bore numerous healthy 

 tips. It was surrounded by a box, whose top and bottom had 

 been removed, as well as some boards from the side. This 

 was partly covered by glass, but plenty of air was allowed 

 entrance. Some of the shoots were so vigorous that they 

 needed no support ; others were long stems and had to be 

 supported. 



On July 18, no glass was used, but record was kept by 

 marks on rods of wood laid above the tip. The movements 

 then obtained were the slowest recorded, and it is likely that 

 the extra protection from wind and retention of heat by the 

 glass cover, produced the quicker movements of August 15. 



When watched in the greenhouse, Lonicera showed itself 

 extremely sensitive to heat ; high temperature invariably 

 being associated with rapid movement. 



Our shortest time is i hour 43 minutes ; Darwin obtained 

 7 hours 30 minutes. He makes no mention of temperature 

 beyond saying "a warm room in the house." The full re- 

 sults obtained are appended. 



Scarlet Runner seedlings were used in the greenhouse for 

 experiment. The panes of the house were whitewashed, and 

 the intensity of light thus diminished. The tips never needed 

 support, young ones being invariably chosen. The results 

 as appended show that the shortest time obtained with this 

 species was i hour. On April 5, we obtained i hour 20 

 minutes, as compared with Darwin's observation on May 2 

 — I hour 55 minutes. 



Wisteria chinensis. — On July 11, young sprouts of this 

 species were found in good condition on a cut-back plant in 

 the greenhouse ; one that had been entirely shorn of branches 



