320 Phillips on a Comparative Study of the 
which they retain but a short time, finally reacting to all 
tests in the same manner as the cell wall of the older 
portions of the Cyanophycez, with which they become 
continuous. 
What the function of these hairs is, I have not been able 
fully to determine. That they are not parasitic growths, 
however, but living portions of the Oscillaria filaments 
which have grown out from the cell protoplasm, either 
through pores specially digested out of the free cell wall 
by means of a ferment, or more likely through the pores 
formerly occupied by the protoplasmic communications 
between the cells (Fig. 35), there can be no doubt. That 
they act more or less as a tactile organ, assisting the trich- 
ome to overcome and get around obstacles met with in the 
forward progress of the filament, was evidenced many times 
in the progress of my observations, for I was able to see 
them swaying from side to side, with a slow but steady 
independent motion as the Oscillaria filaments moved for- 
ward or oscillated. They would apparently reach out on 
one side as if to attach their free ends to something, and 
then gradually sway over until they became bent in the 
opposite direction. If the trichome pressed forward against 
some other object or Oscillaria trichome, these hair-like 
appendages would, through the activities just mentioned, 
apparently determine the way to get around the obstacle, 
as if they were tactile organs that piloted the trichome and 
assisted it in surmounting obstacles. These actions were so 
general and constant that, though I do not consider them 
to be rapid enough to cause the oscillation or creeping move- 
ments, nevertheless, they were such as to convince me that 
I was dealing with a definite plant organ. Having deter- 
mined this, I sought after an adequate cause for the move- 
ments observed. As has been said above, nowhere in the 
whole vegetable kingdom, do such movements, the cause of 
which is understood, occur without ciliary or pseudopodial 
appendages. Various stains and micro-chemical tests were 
