Vines . — On Epinasty and Hyponasty , 423 
experiments with Helianthus dentatus , H. tuber osus , //. pu- 
bescens , Dahlia variabilis , Fuchsia serratifolia , and Urtica 
urens. The leaves of Mirabilis Jalapa behaved in a similar 
manner, but the curvature was slower and less marked than in 
the other cases. My observations as to the position assumed 
in darkness by the leaves of Dahlia and Fuchsia precisely 
agree with those of Krabbe, who used these plants in his 
experiments. 
I made more prolonged observations (four days) on Heli- 
anthus dentatus on the clinostat in darkness. At their first 
development in the apical bud, the leaves, under these circum- 
stances, are perfectly straight, so that their long axes are in 
a line with that of the stem ; then they gradually curve out- 
wards, throughout their whole length, until their long axes are 
at right angles to that of the stem, and finally curve backwards 
till their apices touch the internode behind their insertion. 
In making these observations I was reminded that Batalin 1 
had observed that the growing leaves of certain plants fall, 
whilst others rise, at night ; and it occurred to me that possibly 
the former would react under experiment in the same manner 
as those which I had already observed. Batalin mentions 
Impatiens parviflora , Polygonum Convolvulus , and SidaNapaea , 
as plants whose young leaves fall at night. I made experi- 
ments with the two former, and found that they reacted in 
much the same way as Helianthus. The leaves of P. Convol- 
vulus show this peculiarity when growing in darkness, whether 
on the clinostat or in the normal position, that, as they become 
longitudinally recurved, the lamina becomes revolute, curving 
inwards on both sides towards the under surface of the 
midrib. 
There can be no doubt that these curvatures of the leaves 
are due to epinasty ; either, as in most of the cases, to longi- 
tudinal epinasty alone, or, as in the case of Polygonum Con - 
volvulus , to both longitudinal and transverse epinasty. 
Nor can there be any doubt, in view of the conditions of 
1 Batalin : Ueb. die Ursachen der periodischen Bewegungen der Blumen- und 
Laubblatter. Flora, 1873. 
