252 



CIECUMNUTATION OF LEAVES. Chap. IV. 



qoite fully grown, produced by a lateral shoot, on a young tree 



3 feet in lieight, were observed during 29 h. (July 31st), in the 



Bame manner as the leaves of the previous species. Both these 



leaves certainly circumnutated, making 



Fig. 114. within the above period two, or two and 



a half, small, irregular ellipses. 



(26.) Cycas pectinatu (Cycadese, Fani 

 224). — A young leaf, llj inches in^ 

 length, of which the leaflets had only 

 recently become unciirled, was observed 

 during 47 h. 30 m. The main petiole 

 was secured to a stick at the base of the 

 two terminal leaflets. To one of the 

 latter, 31 inches in length, a filameut 

 was fixed ; the leaflet was much bowed 

 downward, but as the terminal part was 

 upturned, the filament projected almost 

 horizontally. The leaflet moved (see 

 Fig. 114) largely and periodically, for it 

 fell until about 7 p.m. and rose during 

 the night, falling again next morning 

 after 6.40 a.m. The descending lines 

 are in a marked manner zigzag, and so 

 probably would have been the ascending 

 Unes, if they had been traced throughout 

 the night. 



i 



0yca9 pectinata : circum- 

 natatioD of one of the 

 termiDal leaflets, traced 

 from 8.30 A.M. June 

 22nd to 8 A.M. June 

 24th. Apex of leaflet 

 7| inches from the ver- 

 tical glass, so tracing 

 not greatly magnified, 

 and here reduced to 

 one-third of original 

 scale; temp. 19''-2l°C. 



ClKCUMNUTATION OF LeAVES ! 

 MONOCOTTLEDONS. 



(27.) Canna Warscemozii (Cannacese, 

 Fam. 2). — The movements of a young 

 leaf, 8 inches in length and 3J in 

 breadth, produced by a vigorous young 

 plant, were observed during 45 h. 

 50 m., as shown in Fig. 115. The pot 

 was slided about an inch to the right on the morning of the 

 11th, as a single figure would have been too complicated ; but 

 the two figures are continuous in time. The movement is 

 periodical, as the leaf descended from the early morning until 

 about 5 P.M., and ascended during the rest of the evening and 



