198 HOW PLANTS CLIMB. 



The student who is ignorant of the researches on this subject 

 and of their results, leaves unread one of the most fascinating 

 chapters in botanical romance. Prominent among such researches 

 are those of Ludwig Palm and Hugo von Mohl in 1827, of 

 Dutrochet in 1843, of Asa Gray in 1858, of Darwin in 1865, of 

 Fritz Miiller in the following year, and lastly of Hugo de Vries in 

 1873. 



Although gathering information from each of these in part, I 

 take as the chief groundwork of my paper Darwin's book entitled 

 The Movements and Habits of Clhnhing Plants^ which is now, with 

 us, the acknowledged text-book on the subject. It is a small 

 volume compared with most of his works, but none the less does 

 it show the grasp and force of his mighty intellect. I can only 

 give you a very few of the facts from which Darwin deduces the 

 laws which govern the movements of the various classes of 

 climbers— only attempt to lead you across the threshold of the 

 ' Fairy Land of Science ' — only go with you just through the gate 

 which opens at our touch. You must for yourselves explore the 

 field and search for treasure. The treasure is there, and much of 

 it has been spread out to view, by the untiring, unceasing work of 

 Charles Darwin, for those who have eyes, and use them for their 

 right and reasonable purpose. 



Darwin divides climbing plants into four Classes, as follows : — 



I. — Twiners. — Those which tiuijie spirally round some sup- 

 port, unaided by any other movement. ■ 



n. — Climbers. — Those ascending by the aid of sensitive or " 

 irritable organs, which, touching an object, clasp it. This Class is 

 further separated into two Divisions, graduating to some extent 

 into each other : 



A. — Leaf-Climbers. — Those retaining their leaves in a func- 

 tional condition, and climbing by either \h.Q\x petioles, or 

 their produced mid-ribs, or tips ; 



B. — Tendril-Bearers. — Those having true tendrils, these 

 being filamentary sensitive organs, consisting of modified 

 petioles, leaves, fioiuer-stalks, or stipules. 



in, — Hook-Climbers, or Scramblers. — Those climbing 

 simply by the aid of hooks. 



