38 TENDRILS OF TLANTS. 



time to watch the motions of the tendrils of different species 

 of plants ; and I have now the pleasure to address to you an 

 account of the observations I was enabled to make. 

 Experiments The plants selected were the Virginia creeper (the ampe- 



with the Vir-j p S j s q lim quefolia of Michaux,) the ivy, and the common 

 ginia creeper, » 



the ivy, the vine and pea. 



common vine, a plant of the ampelopsis, which grew in a garden pot, was 

 The V. creep- removed to a forcing house in the end of May, and a single 

 er insulated, shoot from it was made to grow perpendicularly upwards, by 

 dril towards a" Deni S supported in that position by a very slender bar of wood, 

 wall eight feet to which it was bound. The plant was placed in the middle 

 of the house, and was fully exposed to the sun j 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. 

 Another plant A P^ ant °^ tne same s P ecies M as placed at the east end of 

 differently situ- the house, near the glass, and was, in some measure, screened 

 TendriUo the' tS ^ rom ^ ie P er P en( Jicular n g nt 5 when its tendrils pointed to- 

 part most wards the" west, or centre of the house, as those under the 

 sia ' 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 

 and when fully w,tn v 'i nes - This plant was then removed to the centre of the 

 illuminated, house, and fully exposed to the perpendicular light, and to 

 turne to an 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, 

 bat not to a It was then removed, and a piece of plate glass was substi- 

 transparent tuted ; bnt to this substance the tendrils did not indicate any 

 ' disposition to approach. The position of the glass was then 



changed, 



