252 



CIKCUMNUTATIOX OF LEAVES. CHAP. IV. 



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

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

 same 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 pectinata (Cycadese, Fam. 

 224). A young leaf, Hi inches in 

 length, of which the leaflets had only 

 recently become uncurled, was observed 

 during 47 h. 30 m. The main petiole 

 was secured to a stick at the base of the 

 two tenninal leaflets. To one of the 

 latter, 3f inches in length, a filament 

 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 

 lines, if they had been traced throughout 

 the night. 



Cycas pectinata : circum- 

 nutation of one of the 

 terminal leaflets, traced 

 from 8.30 A.M. June 

 22nd to 8 A.M. June 

 24th. Apex of leaflet 

 7f inches from the ver- 

 tical glass, so tracing 

 not greatly magnified, 

 and here reduced to 

 one-third of original 

 scale ; temp. 19-2i C. 



ClRCUMNUTATION OF LEAVES: 

 MONOCOTYLEDONS. 



(27.) Canna Warscewiczii (Cannaceae, 

 Fam. 2). The movements of a young 

 leaf, 8 inches in length and 3 in 

 breadth, produced by a vigorous young 

 plant, were observed during 45 h. 

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



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

 llth, 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 



