316 Phillips on a Comparative Study of the 
observation. In one place Wolle claims that the cells begin 
dividing on one side and this concert of division would 
cause that side to become longer and cause a flexion of the 
trichome or the oscillatory motion. In another place he 
considers the creeping motion to be due to the growth and 
multiplication of the cells in the trichome. But as this creep- 
ing motion is in no way accompanied by the oscillation or 
undulatory movement which the one-sided splitting was sup- 
posed to cause, the cells would have to divide evenly on both 
sides, instead of from alternating sides as the first part of 
his theory supposed. 
Here is where observation shows us the fallacies that 
theory alone may build up. The facts are, these cells do not 
begin to divide on one side first, but equally on both sides. 
Moreover, aside from the mathematical alternation from 
side to side, which this theory supposes in the divisions, and 
the unheard-of rapidity with which they must occur in order 
to account for the backward and forward oscillations, if 
there should be an organism in which the partition walls 
were laid down from one side, it would differ from any 
other known cell, and be contrary to the laws of physics if it 
were to swell out that side of the cell more than the other. 
Further, observation also shows us that the trichomes move 
fastest in the daytime, while the cells multiply most rapidly 
in the middle of the night. Even in the night when the 
growth is most rapid and the motion almost stopped— 
probably would be completely so were it not for the light 
necessary in process of observation—the growth can 
scarcely equal the rate claimed by Wolle and his followers. 
Another point overlooked by these investigators, is that both 
ends of the trichome move in the same direction and at the 
same rate of speed, which would be impossible if the multi- 
plication of cells caused the movement. 
Strasburger (75) said: “Simultaneously the threads 
show irregular flexions, or nutations, which are the expres- 
sions of the existing differences in the intensity of growth 
