AUGUST 91 



cannot explain, nearly all the flowers are males, and the 

 few female flowers produce fruit which does not come 

 to perfection. On another pole I have trained Coboea 

 scandens, a very old favourite. As a rapid-growing 

 climber it has few equals, and its flowers, which are 

 like large bells, green at first and then turning to a 

 rich purple, are very ornamental, and when it reaches 

 the latter stage the stamens, which before were well 

 inside the flower, grow to a considerable length, pro- 

 truding far beyond the flower, and twisting themselves 

 in a curious way, for which it is very hard to give a 

 reason. But it is as a climber that the coboaa is such 

 an interesting plant. Darwin, in 1865, in his delight- 

 ful paper ' On the Movements and Habits of Climbing 

 Plants,' which afterwards took a new shape in his 

 larger book on The Movements of Plants in 1880, gave a 

 long description of the movements of coboea. 1 He 

 studied it as ' an admirably constructed climber,' and 

 there is probably no plant from which the method by 

 which plants climb by their tendrils can be better 

 learned. Each shoot ends in a very fine branched ten- 

 dril which stands upright, and each branchlet ends in 

 one or more very delicate claws. The tendril steadily 

 revolves in a circle till it meets with something to 

 which it can attach itself by the little claws. These 

 i See p. 200. 



