314 CLIMBING AND [1864. 



up. When the shoot meets a stick, the motion at that point 

 is arrested, but in the upper part is continued ; so that the 

 climbing of all plants yet examined is the simple result of the 

 spontaneous circulatory movement of the upper internodes. 

 Pray tell me whether anything has been published on this 

 subject ? I hate publishing what is old ; but I shall hardly 

 regret my work if it is old, as it has much amused me. . . . 



C. Darwin to Asa Gray. 



May 28, 1864. 



.... An Irish nobleman on his death-bed declared that he 

 could conscientiously say that he had never throughout life 

 denied himself any pleasure ; and I can conscientiously say 

 that I have never scrupled to trouble you ; so here goes. 

 Have you travelled South, and can you tell me whether the 

 trees, which Bignonia capreolata climbs, are covered with 

 moss or filamentous lichen or Tillandsia ? * I ask because its 

 tendrils abhor a simple stick, do not much relish rough bark, 

 but delight in wool or moss. They adhere in a curious 

 manner by making little disks, like the Ampelopsis. . . . By 

 the way, I will enclose some specimens, and if you think it 

 worth while, you can put them under the simple microscope. 

 It is remarkable how specially adapted some tendrils are ; 

 those of Eccremocarpus scaber do not like a stick, will have 

 nothing to say to wool ; but give them a bundle of culms of 

 grass, or a bundle of bristles and they seize them well. 



C. Darwin to J. D. Hooker. 



Down, June 10 [1864]. 



... I have now read two German books, and all I believe 

 that has been written on climbers, and it has stirred me up to 



* He subsequently learned from where this species of Bignonia 

 Dr. Gray that Polypodium incanum grows. See ' Climbing Plants,' p. 

 abounds on the trees in the districts 103. 



