OF TENTACLES OF RORIDULA. 95 
period of 24 hours it appeared as a small round mass. This, at 
the end of the third day, had diminished in size, and at the close 
of the fourth day, z.e., after 96 hours, had entirely disappeared, or, 
rather, had been digested. 
I then placed a drop of solution of Am, CO, upon one of the 
glands, and found that it became darkened, thus showing that 
the glands have the power of absorption. 
Small cubes of albumen were also placed upon the glands at 
the margin of the leaf, but these were not disolved after a week, 
possibly pointing to the fact that these glands are not digestive. 
I was unable, unfortunately, to conduct sufficient experiments to 
make certain of this fact. 
As might be predicted from their structure al relationships, 
the uni-cellular hairs of the upper surface of the leaf have no 
digestive power. Cubes of albumen placed upon them were 
unchanged after a week. Their function is that probably of the 
similar hairs of R. deniata, to prevent too much transpiration 
from the surface of the leaf, so that as much water as possible 
may be available for the tentacles. 
The plants upon which the above experiments were carried 
out were about five inches high. At the end of the stem there 
were four green leaves which were able to assimilate; below 
these was a single withered brown leaf, the tentacles of which 
were, however, covered by drops of secretion, just as if the leaf 
on which they were situated had been perfectly healthy. I 
placed two small cubes of albumen upon two of these glands, 
and found that, after four days had elapsed these small cubes 
showed no signs of being digested. Shortly after this the upper 
four leaves also withered, and then, and not till then, did the drops 
of secretion upon the glands on this fifth leaf disappear. This 
would seem to point to the fact that the presence of these drops 
of secretion are simply due to hydrostatic pressure. This is the 
more remarkable when it is remembered that there is no vascular 
tissue in the stalk of the ‘tentacles of the Roridula. The 
upper four leaves were able to draw up a sufficient supply of 
water, and some of this transpiration current passing along the 
vascular tissue of the withered leaf found its way to the glands, 
where it appeared in the form of glistening drops, the continual 
evaporation of which would draw up more water and thus keep 
the supply constant. 
