* We were led to observe this plant by Dr. Carl Kraus’ paper, ’Beiträge zur Kentniss der Bewegungen Wachsender Laubblätter,’ Flora, 1879, p. 66.  We regret that we cannot fully understand parts of this paper. [page 251]

the leaf manifestly circumnutated.  It does not appear from the diagram that the leaves move periodically, for the descending course during the first two nights, was clearly due to epinastic

Fig. 113.  Pinus pinaster:  circumnutation of young leaf, traced from 11.45 A.M.  July 31st to 8.20 A.M.  Aug. 4th.  At 7 A.M.  Aug. 2nd the pot was moved an inch to one side, so that the tracing consists of two figures.  Apex of leaf 14 ½ inches from the vertical glass, so movements much magnified.

growth, and at the close of our observations the leaf was not nearly so horizontal as it would ultimately become.

Pinus austriaca.—­Two leaves, 3 inches in length, but not [page 252] 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 within the above period two, or two and a half, small, irregular ellipses.

(26.) Cycas pectinata (Cycadeae, Fam. 224).—­A young leaf, 11 ½ 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 terminal leaflets.  To one of the latter, 3 3/4 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.

Fig. 114.  Cycas pectinata:  circumnutation of one of the terminal leaflets, traced from 8.30 A.M.  June 22nd to 8 A.M.  June 24th.  Apex of leaflet 7 3/4 inches from the vertical glass, so tracing not greatly magnified, and here reduced to one-third of original scale; temp. 19o — 21o C.

Circumnutation of leaves:  Monocotyledons.

(27.) Canna Warscewiczii (Cannaceae, Fam. 2).—­The movements of a young leaf, 8 inches in length and 3 ½ 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 [page 253] part of the night.  On the evening of the 11th it circumnutated on a small scale for some time about the same spot.