18631866] CLIMBING PLANTS 341 



To T. H. Huxley. Letter 665 



Mr. Huxley had doubted the accuracy of observations on Catasetum 

 published in the Fertilisation of Orchids. In what formed the postscript 

 to the following letter, Darwin wrote : " I have had more Catasetums, 

 all right, you audacious ' caviller." 



Down, Oct. 3 ist [1862]. 



In a little book, just published, called the Three Barriers 

 (a theological hash of old abuse of me), Owen gives to the 

 author a new resume of his brain doctrine ; and I thought 

 you would like to hear of this. He ends with a delightful 

 sentence. " No science affords more scope or easier ground 

 for the caviller and controversialist ; and these do good by 

 preventing scholars from giving more force to generalisations 

 than the master propounding them does, or meant his readers 

 or hearers to give." 



You will blush with pleasure to hear that you are of some 

 use to the master. 



To. J. D. Hooker. Letter 666 



[Feb., 1864?] 



I shall write again. I write now merely to ask, if you 

 have Naravelia^ (the Clematis-\\^ plant told me by Oliver), 

 to try and propagate me a plant at once. Have you Clematis 

 cirrhosa ? It will amuse me to tell you why Clematis interests 

 me, and why I should so very much like to have Naravelia. 

 The leaves of Clematzshave no spontaneous movement, nor have 

 the internodes ; but when by growth the peduncles of leaves 

 are brought into contact with any object, they bend and catch 

 hold. The slightest stimulus suffices, even a bit of cotton 

 thread a few inches long ; but the stimulus must be applied 

 during six or twelve hours, and when the peduncles once 

 bend, though the touching object be removed, they never get 

 straight again. Now mark the difference in another leaf- 

 climber viz., Tropceolum : here the young internodes revolve 

 day and night, and the peduncles of the leaves are thus 

 brought into contact with an object, and the slightest 

 momentary touch causes them to bend in any direction and 

 catch the object, but as the axis revolves they must be often 

 dragged away without catching, and then the peduncles 



1 Ranunculaceae. 



