We have here a remarkable instance of the power of light in retarding and hastening the revolving movement. (See ERRATA.)
Convolvulus sepium (large-flowered cultivated var.) moves against the sun. Two circles, were made each in 1 hr. 42 m.: difference in semicircle from and to the light 14 m.
Rivea tiliaefolia (Convolvulaceae) moves against the sun, made four revolutions in 9 hrs.; so that, on an average, each was performed in 2 hrs. 15 m.
Plumbago rosea (Plumbaginaceae) follows the sun. The shoot did not begin to revolve until nearly a yard in height; it then made a fine circle in 10 hrs. 45 m. During the next few days it continued to move, but irregularly. On August 15th the shoot followed, during a period of 10 hrs. 40 m., a long and deeply zigzag course and then made a broad ellipse. The figure apparently represented three ellipses, each of which averaged 3 hrs. 38 m. for its completion.
Jasminum pauciflorum, Bentham (Jasminaceae), moves against the sun. A circle was made in 7 hrs. 15 m., and a second rather more quickly.
Clerodendrum Thomsonii (Verbenaceae) follows the sun.
H. M.
April 12, 1st circle was made in 5 45 (shoot very young)
14, 2nd 3 30
{(directly after the
18, a semicircle 5 0 { plant was shaken
{ on being moved)
19, 3rd circle 3 0
20, 4th 4 20
Tecoma jasminoides (Bignoniaceae) moves against the sun.
H. M.
March 17, 1st circle was made in 6 30
19, 2nd 7 0
22, 3rd 8 30 (very cold day)
24, 4th 6 45
Thunbergia alata (Acanthaceae) moves against sun.
H. M.
April 14, 1st circle was made in 3 20
18, 2nd 2 50
18, 3rd 2 55
18, 4th 3 55 (late in afternoon)
Adhadota cydonaefolia (Acanthaceae) follows the sun. A young shoot made a semicircle in 24 hrs.; subsequently it made a circle in between 40 hrs. and 48 hrs. Another shoot, however, made a circle in 26 hrs. 30 m.
Mikania scandens (Compositae) moves against the sun.
H. M.
March 14, 1st circle was made in 3 10
15, 2nd 3 0
16, 3rd 3 0
17, 4th 3 33
April 7, 5th 2 50
7, 6th 2 40
{This circle was made {after a copious watering with cold water at 47 degrees Fahr.)
Combretum argenteum (Combretaceae) moves against the sun. Kept in hothouse.
H. M. {Early in morning, when Jan. 24, 1st circle was made in 2 55 the temperature of the house had fallen a little.
24, 2 circles each at an }
average of } 2 20
25, 4th circle was made in 2 25
Combretum purpureum revolves not quite so quickly as C. argenteum.
Loasa aurantiaca (Loasaceae). Revolutions variable in their course: a plant which moved against the sun.
H. M.
June 20, 1st circle was made in 2 37
20, 2nd 2 13
20, 3rd 4 0
21, 4th 2 35
22, 5th 3 26
23, 6th 3 5
Another plant which followed the sun in its revolutions.
H. M.
July 11, 1st circle was made in 1 51 }
11, 2nd 1 46 } Very hot day.
11, 3rd 1 41 }
11, 4th 1 48 }
12, 5th 2 35 }
Scyphanthus elegans (Loasaceae) follows the sun.