31 $ Mr. Knight on the Motions 
having presented itself to which they could attach them- 
selves. 
Other plants of the vine, under similar circumstances were 
trained horizontally ; when their tendrils gradually descended 
beneath their stems, with which they ultimately stood very 
nearly at right angles. 
A third set of plants were trained almost perpendicularly 
downwards ; but with an inclination of a few degrees towards 
the north ; and the tendrils of these permanently retained very 
nearly their first position, relatively to their stems ; whence 
it appears that these organs, like the tendrils of the ainpelop- 
sis, and the claws of the ivy, are to a great extent under the 
control of light. 
A few other plants of the same species were trained in each 
of the preceding methods ; but proper objects were placed, in 
different situations, near them, with which their tendrils might 
come into contact ; and I was by these means afforded an op- 
portunity of observing, with accuracy, the difference between 
the motions of these and those of the ampelopsis, under similar 
circumstances. The latter almost immediately receded from 
light, by whatever means that was made to operate upon them ; 
and they did not subsequently shew any disposition to approach 
the points, from which they once receded. The tendrils of 
the vine, on the contrary, varied their positions in every period 
of the day, and after, returned again during the night to the 
situations they had occupied in the preceding morning ; and 
they did not so immediately, or so regularly, bend towards 
the shade of contiguous objects. But as the tendrils of this 
plant, like those of the ampelopsis, spring alternately from 
each side of the stem, and as one point only in three is with- 
