46 MU. DAHWIN ON CLIMBINU PLANTS. 



watched, and the hook remained open for thirty-throe days ; hut 

 during the last week the tip had curled inwards so much that at 

 last only a very thin twig could have heen inserted. As soon as 

 the curling-in of the tip has closed the hook and converted it into 

 a ring, its sensibility, both within and without, is lost ; but as 

 long as the hook remains open its sensibility is retained. 



When the plant had grown from the bulb to the height of only 

 about six inches, the leaves, four or five in number, were broader 

 than those subsequently produced, and their soft and but little- 

 attenuated tips did not form hooks, and were not sensitive ; nor 

 did the stem revolve. At this early period of growth, the plant 

 can support itself; its climbing apparatus is not required, and 

 therefore is not acquired. On the other hand, a full-grown plant 

 which was flowering, and which would not have grown any taller, 

 had leaves on the summit, which were not sensitive, and could not 

 clasp a stick. 



Flaqellaria Indica (Commelynacea>). — From dried specimens 

 it is manifest that this plant climbs exactly like Oloriosa. A 

 young plant, 12 inches in height, and bearing fifteen leaves, had 

 not one leaf as yet produced into a hook or tendril-like filament ; 

 nor did the stem revolve. Hence this plant acquires its climbing 

 power later in life than the Glariosa lily. According to Mold 

 (S. 41), Uvularia (Mclanthaceae) climbs like Qloriosa. 



These three last-named genera are all Monocotyledons ; but 

 there is one Dicotyledon, namely Nepenthes, which is ranked by 

 Mohl (S. 41) amongst tendril-bearers ; and I hear from Dr. Hooker 

 that most of the species climb well at Kew. This is effected by the 

 stalk or midrib between the leaf and the pitcher twisting round 

 any support. The twisted part becomes thicker ; but I observed 

 at Mr. Veitch's that the stalk often takes a turn when not in con- 

 tact with any object, and that this twisted part likewise becomes 

 thickened. Two vigorous young plants of N. Icevis and AT. distil- 

 latoria, in my hothouse, whilst less than a foot in height, showed 

 no sensitiveness in their leaves or power of movement or of climb- 

 ing. But when N. Icevis had grown to a height of 1G inches, 

 there were signs of these powers. Each young leaf when first 

 formed stands upright, but soon becomes inclined ; at this period 

 of growth it terminates in a stalk or filament, with the pitcher at 

 the extremity so little developed that this part is not thicker than 

 any other part. The leaf in this state certainly exhibited slight 

 spontaneous movements ; and when the stalk came into contact 

 with a stick, it very slowly bent round and firmly seized it. But 



