58 PENHALLOW ON MECHANISM 
had been sometime uncoiled, and its movements were noted until there was no further 
motion. The entire period of observation was ten hours and thirty minutes. During 
that time, the tendril tip traversed a distance of 343.15 cm., giving an average rate of 
0.54 cm. per minute. 
The greatest rate of movement, at any one time, was 2.06 cm. per minute, and occurred 
two and one-half hours after the wave of maximum temperature had passed. The waves 
of most rapid movement extended from 2.30 to 4.30 p.m., closely following the greatest 
heat wave. The waves of slowest movement covered the time from 10 a.m. to 2.30 p.m., 
coincident with a rising temperature. The absolute minimum of motion occurred just 
before the maximum of temperatttre, at the rate of 0.21 cm. per minute. At four o’clock 
in the morning, a heavy rain ceased. The air was surcharged with moisture, and the 
sky was entirely overcast with heavy clouds. It was while this condition lasted, that 
the waves of slowest motion occurred, the absolute minimum being found during the 
period from 12.15 to 1 p.m. At the latter hour, the clouds broke and the sun came out 
brightly and so continued until6 p.m., when the sky again became overcast and rain set 
in at 7 o’clock. While the sun was out, the tendril was most active—the absolute 
maximum of motion taking place within the five minutes from 3.25 to 3.30 p.m., the 
distance travelled in that time being 16.30 cm. 
The first direction of movement was to the right. This, however, was obviously 
accidental, since the direction first recorded must depend upon the time of first observation 
with relation to the entire movement—dextrorse alternating with sinistrorse movement 
during the whole period of activity. The total motion to the right was 190.8 cm.; that 
to the left, 152.35 cm. ; and the ratio therefore, as 1: 0.79. 
Tendril No. 2.—Selected for observation, August 13th, at 8 o’clock. It was a shorter 
arm than No. 1, and somewhat nearer the end of activity. The time of observed 
movement was six hours and fifteen minutes, and the whole distance travelled 136.00 cm., 
thus giving an average rate of 0.36, cm. per minute. 
The absolute maximum of motion was 1.76 cm. per minute and occurred from 10.15 
to 10.20 a.m., forty-five minutes before the maximum temperature for the day was reached. 
The waves of most rapid motion covered the period from 8 to 10.50 a.m., coincident with 
increasing temperature. The waves of least motion occurred between 10.50 a.m., and 
2 p.m., during a slight depression of temperature. The absolute minimum was reached 
between 10.50 a.m. and 12.25, and amounted to 0.179 cm. per minute. It directly succeeded 
the maximum of temperature. During the entire time of observation, the weather was 
very pleasant, though somewhat cloudy. At 12 o'clock, the leaves began to droop from 
the effects of excessive heat and transpiration. This continued until after the close of 
observations. It was during this time of depressed activity, that the minimum motion 
occurred. During the entire morning, all the leaves and flowers showed great vigor, and 
it was while in this condition that most active movement took place. The first motion 
observed, was to the left, and was not replaced by dextrorse for some time. The entire 
sinistrorse action was 94.2 cm.; the dextrorse, 41.8 cm.; and the ratio of the latter to the 
former was therefore, as 1 : 2.25. 
Tendril No. 3.—The time of observation was ten hours and thirty minutes, commenc- 
