Mr. Knight on the Motions , &c. 315 
of the house, and was fully exposed to the sun ; and every 
object around it was removed far beyond the reach of its ten- 
drils. Thus circumstanced, its tendrils, as soon as they were 
nearly full grown, all pointed towards the north, or back wall, 
which was distant about eight feet : but not meeting with any 
thing in that direction, to which they could attach themselves, 
they declined gradually towards the ground, and ultimately 
attached themselves to the stem beneath, and the slender bar 
of wood. 
A plant of the same species was placed at the east end of 
the house, near the glass, and was in some measure skreened 
from the perpendicular light ; when its tendrils pointed to- 
wards the west, or centre of the house, as those under the 
preceding circumstances had pointed towards the north and 
back wall. This plant was removed to the west end of the 
house, and exposed to the evening sun, being skreened, as in 
the preceding case, from the perpendicular light ; and its ten- 
drils, within a few hours, changed their direction, and again 
pointed to the centre of the house, which was partially covered 
with vines. This plant was then removed to the centre of the 
house, and fully exposed to the perpendicular light, and to 
the sun ; and a piece of dark-coloured paper was placed upon 
one side of it just within the reach'of its tendrils ; and to this 
substance they soon appeared to be strongly attracted. The 
paper was then placed upon the opposite side, under similar 
circumstances, and there it was soon followed by the tendrils. 
It was then removed, and a piece of plate glass was substi- 
tuted; but to this substance the tendrils did not indicate any 
disposition to approach. The position of the glass was then 
changed, and care was taken to adjust its surface to the varying 
