120 CLIMBING PLANTS. 



sweeps a circle (according to the length of the bending 

 shoot and the length of the tendril) of from one foot to 

 twenty inches in diameter, and immediately that the tendril 

 touches any object, its sensitiveness causes it immediately 

 to seize it. A clever gardener, my neighbor, who saw the 

 plant on my table last night, said : " I believe, sir, the ten- 

 drils can see ; for wherever I put a plant it finds out any 

 stick near enough." I believe the above is the explanation, 

 viz., that it sweeps slowly round and round. The tendrils 

 have some sense, for they do not grasp each other when 



young. 



Yours affectionately, 



C. DARWIX. 



Here he has found the explanation of the 

 curious fact which we noticed in the beginning of 

 this article. Two years later his paper on " Climb- 

 ing Plants " was printed in the Journal of the 

 Linnsean Society, and in 1875 the essay was re- 

 vised and published as a separate book. 



Darwin divides climbing plants into four classes : 

 (1) Twiners, or plants which climb by the stem 

 winding about its support. (2) Leaf-climbers and 

 tendril-bearers, plants which possess irritable 

 organs by which they grasp any object with which 

 they come in contact. (3) Hook-climbers. (4) 

 Root-climbers, which attach themselves by means 

 of aerial rootlets. The last two classes have no 



