Cnap. XIV. ALDROVANDA VESICULOSA. 325 
On the concave gland-bearing portion of the lobes, 
and especially on the midrib, there are numerous, 
long, finely pointed hairs, which, as Prof. Cohn re- 
marks, there can be little doubt are sensitive to a 
touch, and, when touched, cause the leaf to close. 
They are formed of two rows of cells, or, according to 
Cohn, sometimes of four, and do not include any vas- 
cular tissue. They differ also from the six sensitive 
filaments of Dionza in being colourless, and in having 
a medial as well as a basal articulation. No doubt it 
is owing to these two articulations that, notwithstand- 
ing their length, they escape being broken when the 
lobes close. 
The plants which I received during the early part 
of October from Kew never opened their leaves, 
though subjected to a high temperature. After ex- 
amining the structure of some of them, I experimented 
on only two, as I hoped that the plants would grow; 
and I now regret that I did not sacrifice a greater 
number. 
A leaf was cut open along the midrib, and the 
glands examined under a high power. It was then 
placed in a few drops of an infusion of raw meat. 
After 3 hrs. 20 m. there was no change, but when 
next examined after 23 hrs. 20 m., the outer cells of 
the glands contained, instead of limpid fluid, spherical 
masses of a granular substance, showing that matter 
had been absorbed from the infusion. That these 
glands secrete a fluid which dissolves or digests animal 
matter out of the bodies of the creatures which the 
leaves capture, is also highly probable from the 
analogy of Dionewa. If we may trust to the same 
analogy, the concave and inner portions of the two 
lobes probably close together by a slow movement, as 
suon as the glands have absorbed a slight amount of 
