TENDRILS 191 



long, green, spiral springs, and its free, branching,, 

 young tendril tips reaching out in all directions 

 for fresh foothold, and in its absence content at 

 length with a friendly intertwining among them- 

 selves, and a consequent tangle of green convolu- 

 tions. It is hard to believe that these long, out- 

 reaching arms at the summit of this vine are 

 identical with the closely twisted spirals below, 

 but such is the case; let any one of them once 

 feel the contact of even the frailest support of 

 twig or stalk, and it is soon close in the embrace 

 of its eager tip, and the contraction of the spring 

 commences, but the method of this contraction is 

 worth our study. 



In order for this tendril to coil it must twist, 

 and it is perfectly plain on general principles that 

 with both ends held fast twisting is impossible. 

 But this little paradox is evidently dismissed by 

 the tendril. If we tie a short string between two 

 given points, and attempt to twist it with our fin- 

 ger and thumb, we succeed in turning the string, 

 'tis true, but the twist on the right side neutral- 

 izes that on the left, being in the opposite direc- 

 tion. In this way only can the cord be twisted. 

 If we twist with sufficient patience we may imi- 

 tate the coil of the tendril, which is performed pre- 

 cisely in this way. Herein lies the secret of that 

 little loop or kink in the centre of all tendrils 

 a given point, which cannot be determined on the 



