ON THE ADHESIVE DISCS OF ERCILLA VOLUBILIS. 95 
The Adhesive Dises of Ercilla volubilis, A. Juss. By J. H. 
BurraGt, M.A., Junior Assistant to the Professor of Botany 
in the University of Edinburgh. (Communicated by Prof. 
J. BRETLAND Farmer, M.A., F.L.S.) 
[Read 18th February, 1897.] 
(Prate 5.) 
Ercttta voLvBILIs, A. Juss. (syn. E. spicata, Moq.), a Phyto- 
laceaceous climber, is a native of Chili, first introduced into this 
country by Bridges, and hence known also under the name of 
Bridgesia, Hook. & Arn. (non alior.). 
Although by no means hardy, it is frequently found in gardens 
in this eountry as an ornamental shrub ; in sheltered positions it 
flourishes fairly well, and even bears flowers in exceptionally 
warm summers. It is usually found in cultivation trained up a 
flat wall, but this is obviously not its natural habit. If left to 
itself the branches fix themselves on to any available support by 
means of adhesive dises, borne immediately above the axils of 
the leaves. 
In the stem immediately opposite the base of the axillary 
buds there is a break in the continuity of the vascular ring, 
caused by the departure of the bud-bundles. A number of pith- 
cells, which occupy the normal position of the bundles at this 
Point, become lignified in precisely the same manner as described 
"» case of Manihot Glaziovii, Muell. Arg.* It is suggested 
iens i lignification of these cells takes place in order to 
ih AD stem at this point, but it is equally probable 
the trees M walls of which are deeply pitted) may assist 
the bese NA current by forming a connecting bridge across 
e branch +. 
"ni ies Which support the stem are, when fully developed, 
2 1n. long and 4 in. in breadth, each one converging to a 
roseo the stem above the leaf and sending down a small 
t M on on either side of the base of the petiole, and thus has 
(fi Donee of a slightly projeeting, heart-shaped shield or disc 
' it is, however, only those in actual contact with the 
* 
Calvert & Boodle, * Annals of Botany, 
he result of 
tracing th 0t a se 
Various 
Cases th 
Dorma] 
: vol. i. p. 58. 
e path of th es of experiments recently made, with the object of 
stains, tend 9 transpiration current, by means of weak solutions of 
tended to show that the former is the correct view. In all 
e ligni : - 
eode Pith-cells opposite the bud remained unstained, while the 
"ng wood was uniformly coloured. 
