DEDUCTION. GENERAL INSTANCES. 1/3 



more common with plants, as we shall presently 

 see, than is generally supposed to be the case 

 by those who have not attended to the subject. 

 There is, however, the one remarkable case of 

 the Maurandia semperflorens, in which the 

 young flower-peduncles spontaneously revolve 

 in very small circles, and bend themselves when 

 gently rubbed to the touched side; yet this 

 plant profits in no way by these two feebly 

 developed powers. A rigorous examination of 

 other young plants would probably show some 

 slight spontaneous movements in the peduncles 

 and petioles, as well as that sensitiveness to 

 shaking observed by Hofmeister. We see, at 

 least in the Maurandia, a plant which might, 

 by a little augmentation of qualities which it 

 already possesses, come first to grasp a support 

 by the flower-peduncles, as with Vitis and Car- 

 diospermum, and then by the abortion of some 

 of its flowers acquire perfect tendrils." 1 At 

 this point he made the prediction already 

 quoted. 



To sum up, Darwin based his conclusions 

 concerning the source of the power of revolving 

 upon the following data: (i) detailed knowledge 

 of the nature and extent of the climbing power 

 in the plant kingdom ; (2) proof that there are 



1 Journal, p. 113. 



