OF MOVEMENT IN PLANTS. 63 
the very commencement of observation, and on a rising temperature, six hours before the 
maximum was reached. The waves of most rapid motion were found from 8 to 11.30 a.m. 
Least motion took place at 1.30 to 2 p.m., at the rate of 0.08 cm. per minute. This was 
just at the time of maximum temperature. The waves of least motion were found from 
11.30 a.m. to the close of observations at 3.40 p.m., coincident with a rising and maximum 
temperature. 
Observations commenced with a moderate temperature, clear sky and an active 
condition of the plant, continuing thus during the time of greatest movement, until, at 11 
o'clock, the leaves became depressed from the effects of the heat, and from 11.30 on, the 
waves of slow motion were found. At 12 m., the sky was overcast and the air loaded 
with moisture. At 1p.m., the leaves were restored to their normal condition and erect 
position. At the same hour, rain commenced and continued during the remainder of the 
experiment. The total movement to the right was 25.10 cm.; to the left, 69.30 cm., and 
the ratio as 1: 2.76. 
Tendril No. 8a—Selected Aug. 16th, at 9 a.m.—The time of observation covered a 
period of nine hours and fifty minutes, or until 6.50 p.m. The entire movement during 

that time was 314.50 cm., giving an average rate per minute of 0.516 cm The time of 
greatest movement was from 3 to 3.15 p.m., and the rate per minute 1.20 cm. This was 
on a decreasing temperature, four hours and fifteen minutes after the maximum. The 
waves of greatest movement were found from 2 p.m. until the end of observations, and 
during a diminishing temperature. 
The time of least movement was from 11.25 to 11.40 a.m., and the rate per minute 
0.166 cm. This was at the time of maximum temperature. The waves of slowest 
motion extended from 9 a.m. until 2 p.m., with slight acceleration of movement towards 
the latter hour. Observations commenced with a bright sun and the plant in active 
condition. At 12 o’clock, the leaves drooped, with the thermometer at 34.4° C, and this 
condition continued until early in the afternoon, when they revived with decrease of 
heat. It was during the passive condition of the plant that the slowest motions were 
observed, the more rapid waves occurring with renewed vigour and greater tension of 
parts. The entire dextrorse motion was 143.10 cm.; the sinistrorse 161.40 cm., and the 
ratio, therefore, as 1 : 1.12. 
Tendril No. 8 b.— Observations were resumed at 8 o’clock a.m., August 17th, and 
were continued for seven hours and forty-five minutes. The distance which the tip 
travelled during that time was 225.0 cm., or at the average rate of 0.483 cm. per minute. 
The greatest movement was at the rate of 2.60 cm. per minute, occurring from 3.40 to 
3.45 p.m., at the very close of observations and one hour and forty-five minutes after 
the maximum of temperature. The waves of most rapid movement were from 8.15 
to 3.45 p.m. Least movement occurred at 10.15 to 10.30 a.m., at the rate of 0.10 cm. per 
minute. The waves of least motion extended from 8 a.m. until 3.15 p.m., coincident with 
a rising and maximum temperature. Observations commenced with a bright sun and 
the plant active. At 11 o’clock am., just thirty minutes after the minimum of motion 
occurred, the leaves were all drooping as a result of excessive transpiration. At 1 o’clock 
_ p.m., it was raining, and the normal activity of the plant was restored. This continued 
