1903.] 



The Statolith-thcorij of Geotropism. 



367 



the tuning fork. In this case any acceleration in the line of the fork 

 would be in favour of the " still " specimens. 



Table I requires a few words of explanation. The third column 

 gives the number of the experiment and simply refers to the original 

 notes. The next column gives the time in minutes during which the 

 plants were left horizontal. Then follow the temperature and the 

 length of time during which the plants were left on the klinostat. 

 When two readings occur under this column it means, of course, that 

 the curvature was measured more than once : thus in experiment 74 

 the curvature was read after 4 hours' rotation, and again after 6h. 33m. 

 from the time at which the plants were originally placed on the 

 klinostat. The column " Shaken " gives the angular deviation from 

 the horizontal of the plants which had been on the fork ; their average 

 curvature follows in a separate column. The last two columns give in 

 the same way the actual observations and the average for the control 

 plants. For the sake of brevity we use the terms " Shaken " and 

 " Still "for the experimental and control plants. In columns " Shaken 

 and "Still" the letter x occurs occasionally in brackets, thus (x) : this 

 means that nutation downwards or sideways had occurred. In the 

 same way (5) indicates a downward or lateral nutation of 5°. In 

 striking averages, I have counted the nutating specimens and also 

 those which showed no geotropism, i.e., remained horizontal. Thus, 



45 



if the readings were 13, 15 (x) 17, the average would be — = 11*3: 



or if it had been 13, 15, 0, 17, the average would have been the same- 

 When the cases of nutation were very frequent, or where the curvature 

 occurred very slowly, as in experiments 131, 140, I have omitted the 

 average curvature from consideration, although I have allowed the 

 readings to remain in the table. 



The first thing that strikes one is that the shaken specimens show a 

 greater curvature than the still ones in a large majority of cases. 



Thus, taking the whole of the thirty cases in which the average 

 curvatures are calculated, we have : — 



Shaken, curvature greater in 25 cases. 



,, equals or practically equals still 3 

 Still, greater than shaken 2 



Out of these thirty cases, seven are second readings, i.e., records of 

 curvature in experiments in which readings had been taken a few 

 hours previously. If these are omitted, we get : — 



SJmken, curvature greater 19 



,, equals still 2 



Still, curvature greater 2 



Finally, there are four cases in which the plants were left on the fork 



