158 TENDEIL-BEAREKS. Chap. IV. 



species. Tlie tendrils are thick, long, and stiff ; they 

 are sensitive to a touch only on the concave surface 

 towards the extremity. When a stick was placed so 

 that the middle of the tendril came into contact with it, 

 no curvature ensued. In the hothouse a tendril made 

 two revolutions, each in 2 hrs. 22 m. ; in a cool room 

 one was completed in 3 hrs., and a second in 4 hrs. 

 The intemodes do not revolve; nor do those of the 

 hybrid P. floribuncla. 



Tacsonia manicata. — Here again the intemodes do 

 not revolve. The tendrils are moderately thin and 

 long ; one made a narrow ellipse in 5 hrs. 20 m., and 

 the next day a broad ellipse in 5 hrs. 7 m. The 

 extremity being lightly rubbed on the concave surface, 

 became just perceptibly curved in 7 m., distinctly in 

 10 m., and hooked in 20 m. 



We have seen that the tendrils in the last three 

 families, namely, the Vitaceae, Sapindacese and Passi- 

 floraceae, are modified flower-peduncles. This is like- 

 wise the case, according to De Candolle (as quoted 

 by Mohl), with the tendrils of Brunniehia, one of the 

 Polygonaceae. In two or three species of Modeeea, one 

 of the Papayaceae, the tendrils, as I hear from 

 Prof. Oliver, occasionally bear flowers and fruit ; so 

 that they are axial in their nature. 



The Spiral Contraction of Tendrils. 

 This movement, which shortens the tendrils and 

 renders them elastic, commences in half a day, or in a 

 day or two after their extremities have caught some 



