THE 
MOVEMENTS AND HABITS 
OF 
CLIMBING PLANTS. 
CHAPTER IL 
TwIninc Pants, 
Introductory remarks—Description of the twining of the Hop—Torsion 
of the stems—Nature of the revolving movement, and manner of 
ascent—Stems not irritable—Rate of revolution in various plants— 
Thickness cf the support round which plants can twine—Species 
which revolve in an anomalous manner. 
I was led to this subject by an interesting, but short 
paper by Professor Asa Gray on the movements of the 
tendrils of some Cucurbitaceous plants.* My obser- 
vations were more than half completed before I learnt 
that the surprising phenomenon of the spontaneous 
revolutions of the stems and tendrils of climbing 
plants had been long ago observed by Palm and by 
Hugo von Mohl,f and had subsequently been the 
subject of two memoirs by Dutrochet.{ Nevertheless, 
* ¢Proc, Amer. Acad. of Arts pflanzen,’ 1827. Palm’s Treatise 
and Sciences,” vol. iv. Aug. 12, was published only a few weeks 
1858, p. 98. before Mohl’s. See also ‘The Ve- 
+ Ludwig H. Palm, ‘Ueber das getable Cell’ (translated by Hen- 
Winden der Pflanzen ;’ Hugo von frey), by H. von Mohbl, p. 147 to 
Mohl, ‘ Ueber den Bau und das_ end. 
Winden der Ranken und Schling- t “Des Mouvements révolutifs 
