PROCEEDINGS. OF SOCIETIES. 89 
1. *0020232 inch a5 pean on Ur qpAur 2% Cloudy. 
2. 0029436 » » QUIPPE oo eloudy. 
9: "0035277 my » eo SOS A A ee cloudy. 
: 0051108 b 5 . 11 Aa... bright sun. 
18324 P 3 . . 12 noon. . bright sun. 
'00 
Mean "0047292 
The mean of the five experiments giving a velocity of 0047292 inch 
per second. The greatest velocity, experiment 5, was obtained in bright 
in the forenoon and afternoon, the sun being more or less obscured 
ssing clouds. As Sachs has slated the velocity on the amount 
transpired in one hundred and ten hours, the mean is cha than that ob- 
tained by spectroscopic observation, —the short duration of the experi- 
ments, together with the time of day, fip temperature, and brighter 
light, easily accounting for the difference. I am indebted to the Rev. J. 
Constable, M.A., Principal of the Royal Agricultural College, Cirencester, 
for some of the calculations required in this paper. 
pelopsis Veitchii.” By W. R. M'Nab, M.D. Edin. While visiting J. 
directed 
are furnished with disk-like suckers, several of them occurring on one 
tendril and forming a very strong support. At first these appear as bodies 
resembling very much the head of a small pin, and afterwards they de- 
velope with flat disks. Sachs (Lehrbuch der Botanik, p. 672) mentions 
that in Ampelopsis hederacea the tendrils develope disks which secrete a 
sticky substance and thus adhere to walls, etc. Darwin found that the 
old dry disks would support a great weight ; one tendril with five disks 
supporting no less than ten pounds. he tendrils of Ampelopsis are, like 
to be co t of the 
tendril, a slight club-s shaped sw swelling is observed. This rapidly grows 
into a disk, by the development of a large branching hair from every cell 
of the epidermis of part of the "tmn end of the tendril which is 
next the body to be adhered to, and, therefore, that part which is most 
shaded from the light. As every cell produces a hair, the original epi- 
rmis is entirely lost. These hairs are glandular and secrete a sticky 
substance, which enables the disk to ethers to the wall or other support. 
The cells in the centre of the disk rapidly enlarge and become thickened, 
the dry walls having a well-marked pitted appearance These tendrils 
have but little to coil round any fixed object, but are markedly 
influenced by light. ey turn away from the light, as does also the 
whole branch, and, therefore. rdg a very well-marked example of nega- 
tive Heliotropism. The interest in these tendrils is considerable— first, 
o 
stals 
calcium íslams are to be met ot with. Eia am indebted to J. re: ee 
Henry, Esq., of Hay Lodge, for the specimens examined.—“ Note on 
* 
