THE REVERSED SPIRAL 237 



But every turn in the opposite direction takes off 

 twist, and a tendril twisted fifteen times from right 

 to left and fifteen times from left to right is not 

 strained at all. 



There is another advantage in the reversed spiral ; 



FIG. 60. Red Bryony, with two tendrils, one free, the other clinging to a branch of 



it can be pulled out straight without a kink. Pull at 

 the ends of a continuous spiral, and the turns cannot 

 be effaced, though they may be reduced to as many 

 twists. 



