930 REPORT—1899. 
Section II. contains observations and remarks relating to the carbohydrates of 
latex. g 
Sugar in variable proportions is of frequent occurrence in latex. The little 
contained in the trunk-latex of Hevea seems to be cane-sugar. 
It is suggested that the sugar may arise, in part at least, from the surrounding 
injured tissues, and may not be always originally present in the latex. 
The starch-rods so characteristic of the laticiferous tubes of Huphordia and 
allied genera have been found still present in the turned and fallen leaves of the 
following species examined: Euphorbia pulcherrima, E. Bojeri, E. rothiana, Pedi- 
lanthus tithymaloides, Hura crepitans, Exvcecaria bicolor, and Sapium biglandu- 
losum. This fact is somewhat opposed to the view of these tubes functioning as 
conductors of starch from the leaf. 
In Section IIL. reasons are given for thinking that in some caoutchoue trees 
the latex of the young stems and leaves differs in the composition of its globules 
in suspension from that of the trunk and main branches. While the latter yield 
rubber free of stickiness, the former give a somewhat viscous substance with 
feeble elasticity. Such is the case with Hevea, Castilloa, Landolphia Kirkii, Ficus 
elastica, and Urceola eseulenta. 
Section IV. treats of an important fact connected with the tapping of Hevea 
trees, viz., that wounding the bark causes a greater flow of latex from subsequent 
injuries. A point first indicated in the experiments of Mr. Willis, who found that 
the weight of rubber obtained from the second tapping was about double that 
from the first. The author has followed this up with some instructive results. 
In Section V. a peculiarity in the exudation of latex from the severed base of 
the petiole of Hevea brasiliensis and Plumiera acutifolia is described and 
discussed. : 
In Section VI. a special laticiferous system developed in the immature seed of 
Hevea brasiliensis is brought to notice. 
The paper concludes with general remarks and suggestions on the origin and — 
functions of laticiferous tissue. 
8. Intumescences of Hibiscus vitifolius (Z.). By Miss E. Datz, Cambridge. 
I. Anatomical Part. 
The plants on which the following observations were made were grown, directly 
or indirectly, from seed from Somaliland. The intumescences, which vary in size 
and shape, occur on the leaves, stems, green parts of the flower, and on the young 
fruit. Some are entirely colourless; others are green at the base. Those on (1) 
the leaf differ from those on (2) the stem. 
1. On the leaf the intumescences are of two types. 
(a) Purely epidermal. 
(8) Partly sub-epidermal. 
a. The purely epidermal and smaller type consists of one or two tiers, of much 
elongated, thin-walled cells, usually twisted spirally round one another. At the 
apex is a stoma, which may or may not lead into an intercellular space. 
8. The larger outgrowths contain basal prolongations of parenchyma. 
2. On the ste the outgrowths are more complex, and usually larger. The 
basal part consists of elongated sub-epidermal cells divided by periclinal walls. 
The upper part is made up of much enlarged, thin-walled epidermal cells, similarly 
divided. The outgrowths later become cut off by cork, which arises in the lowest 
row of daughter cells derived from the original epidermis, z.c. in the lowest 
colourless cells; after suberisation of these cells the outgrowth shrivels. 
Il. Experimental Part. 
Seedlings were raised in the Tropical Pit, and eight of them were planted, each 
in a separate pot, and allowed to grow on under identical conditions. They all 
O4 
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