Notes. 
362 
a deposit on the surface and in the cells of the tree which contains 
85-81, or nearly 86 per cent, of calcium carbonate. 
(Signed) J. H. HART, 
Superintendent. 
D. Morris, Esq., M.A. 
As an addendum to the report upon the exudation upon ‘Tapana’ 
wood I should mention that the soil near which the tree was grown 
contained on analysis the following : — 
Moisture at 212 F. . . . . . . 1-24 
Water of combination and organic matter . . 3-86 
Oxides of iron and alumina with phosphates -08 . 7-73 
Lime . . . . . . . . -15 
Sulphuric Acid ....... Traces 
Magnesia . . . . . . . . -18 
Potash . . . . . . . . -io 
Soda ......... Traces 
Silica, sand, &c. . . . . . . .86-74 
Total ioo-oo 
W. T. THISELTON DYER, Kew. 
ON THE POWER OP CONTRACTILITY EXHIBITED 
BY THE PROTOPLASM OP CERTAIN PLANT CELLS.— 
In a communication to the Royal Society (see Roy. Soc. Proc., No. 
240, 1886), I gave some account of the principal changes which take 
place in the gland-cells and stalk-cells of Drosera dichotoma during 
secretion, and later I gave a preliminary account (see Roy. Soc. Proc., 
No. 260, 1887) of certain experiments and observations which were 
undertaken in order to attempt to ascertain by what mechanism the 
bending of the tentacles is made possible in Drosera , and what changes 
occur in the tentacle-cells. I hope shortly to publish a full account 
of my observations in the f Annals of Botany/ but in the meantime the 
following note, which is almost a reprint from the Roy. Soc. Proc., will 
indicate the line of my work. 
During actual movement no obvious histological changes can be 
detected in the cells of the bending portion, but when the tentacle 
has become well inflected, it becomes apparent that the cells of the 
