243 
pound, and it may be doubled that as much as fr. 6 25 per 
kilogramme would be obtained. 
Plants of Willughbeia firma cultivated in the Botanic Gardens 
for a number of years, and either raised on trellises or allowed to 
spread along the ground, in full sun, form thick masses of rather 
slender twigs. The largest I notice in plants about 13 years old 
are f inch thick. They are very leafy and dense, but do not 
develop into the stout lianes so often to be met with in forests. 
Twigs and leaves, however, are full of rubber, which exudes when 
the fresh twigs are cut. A few hours, however, after being cut, 
the twigs, if cut or broken, exude no more, unless they are heated 
at one end, when the latex begins to exude again with the sap, 
from the other. It may be possible to use this principle in dealing 
with Willughbeia growm in bush form in the open, or the plants 
might be cut and crushed with a machine which would press out 
the rubber, in such a manner that it could be economically col- 
lected. It would, however, be also worth while to plant the 
Willughbeias in the patches of forest usually preserved near es- 
tates, and allowing them to grow as they like, tap out the lianes 
when they attain a sufficient thickness to be conveniently 
tapped. In this way there would be hardly any expense con- 
nected with the cultivation except in the original planting and 
tapping. Any of the other rubber vines mentioned in this paper 
might be grown in the same way, but besides W. firma the best 
for this purpose would be W. flavescens and W. coriacea , Leucono- 
tis Grifjfithii and eugenicefolius and the Urceolas. 
The L'andolphias of Africa seem to me even more suited for 
this class of culture than our own rubber vines. 
L Heudelotii and A. sp. have made remarkably rapid growth 
in the open, and their stems under these circumstances attain a 
greater thickness than do the Willughbeias, but there seem to be 
some doubt as to the value of the latex of L. Heudelotii. 
The following dimensions of the branches of various rubber 
vines cultivated in the Botanic Gardens may show the different 
values of the plants as regards growth. All are grown in the same 
class of soil, rather stiff inferior clay, and the measurements are 
from branches and not of the stumps, which are much thicker : — 
Willughbeia firma about 13 years, f inch diameter. 
Leuconotis eugenice folia 13 ,,3 inches ,, 
Landolphia Heudelotii 4 ,, 2 ,, ,, 
L. florida? 3 ,,2 ,, ,, 
Urceola braghysepala 10 ,, f- ,, ,, 
W I Ok-, , 1/(4 Wall.-— Stems stout, 4 inches through with thick 
waited black bark, dark red inside, tendrils, long, slender with 
few curved branches. Leaves very coriaceous elliptic obtuse, 
nearly lanceolate when young, deep green above, light green be- 
neath (drying red), 3^- to 5 inches long, 2 to 3 inches wide or 
smaller, nerves obscure, hardly raised 7 to 8 pairs, petiole thick 
dark brown, \ inch long. Flowers crowded in very short axillary 
tufts, about 6 inches a tuft almost sessile, Calyx very small with 
short ovate lobes minutely ciliate, Corolla tube short dilated in 
