[100]

Mimosa pudica

June 1877

I must pin open leaf & use drops of water at 90º or 94º. This will be only way to do thing securely.—

One leaf pinna on which drop rested for some time is a little burst, 1 in 2 of leaflets; but 2 other pinnæ on which drops were often placed were not in the least affected.

Drops often renewed nearly on same spot— for 3 or 4 days, & yesterday intensely hot.—

The best plan wd be to put drop on slides as often as on leaflets. I might cut off opposite leaflet.

N. B. In all future experiments with drops of water on leaves, after cleaning off bloom, syringe surface with distilled water & then put on drops, for I suspect loose particles of wax, chief cause of difference. Also aways place few drops of water in watch-glass near by.—

[100v]

I must observe about 1' hour leaf not having bloom

(Shake a mimosa & place in heavy rain & if leaves open see if they are wetted.)

[101]

1877

Mimosa pudica

July 9th 8º 30'  leaflet pinned open on loose cork with finest pin & opposite leaflets cut ope off— cleaned with camel-brush— was delicately washed with water at 90º.

Left leaf drops put on 8º  30' & drops, same number on slip of glass.

The water now runs off so easily impossible to keep drops long on.—

Right leaf rather younger leaf 1 leaflet 11º 30'— (Often left dry for a space so wd respire

July 14th 8º 30' freed the leaves — the main petioles spring up & most of all the leaflet, which had been pinned down were still sensitive & moved moved when touched.

Left-hand leaf older to two white wool

Right ─ ─ younger ─ Black wool.

The white-wool leaflets do not appear in the least injured (16th not injured!) but the black-wool have brown marks, not near pin-holes (excessively minute holes)— The leaves lay on cork & had been so well cleaned that water wd not stay on them in drops but ran on cork, so that they were damp above & below for the 5 days. All the leaflets were occasionally left dry— so that spot cd respire.

All the leaflets go to sleep & are sensitive during day so not injured. (over)

[101v]

July 19th 10º There were 3 leaflets on the younger leaf

Black wool thus treated & I have examined them under compound.— The inner cel Considerable brown marks, & these seems due to the inner cells, which are surrounded by brown matter, I suppose dead protoplasm, best seen near borders where injury small. — Also margin of leaf injured.

July 21st 8º A.m. The leaflets on older leaf (white wool) which I thought uninjured have now been examined: the milled edges appear hardly injured; but under lens several specs pale yellowish brown & clearly dead; veins browned; & I examined many other leaflets on same pinna pinnas & none presented any such appearance. x

x I have looked again with 1/10th inch, as temporal object & wherever there are pale- brownish marks on surface the leaflet is far more transparent showing that injury has travelled far down into substance of leaf.—

(N.B. on this pinna hairs on mid-rib & margin of leaf have secreted globules of dark red apparently resinous substance. This secretion no relation to water, & not from Hairs.

[102]

Mimosa pudica

July 23d 12º— rubbed several leaflets with small & gentle camel-brush & water at 90º, but the drops will not remain well on & run run off, so that leaves often generally left dry or merely damp.

Aug. 2d  I can see no effect produced.

(July 28th   10º 45' cleaned the lower surfaces of 2 right-hand pinnæ on both sides with water at 90º, & fastened on weight & submerged leaf.

Aug 6th examined carefully above 2 leaves: the older younger of the two is no way materially injured, except a few minute brown specks.—

The older leaf with 5 leaflets all of which have mid-ribs from 1/3 or even 1/2 of length of leaflet pale yellowish-green, & from some little distance on each side; somewhat more transparent; no appearance of the kind on the other leaflets on the same pinna, on which water had not been placed.—

[103]

1877 Mimosa pudica

Aug. 8' 9º 15  a leaf placed under the dripping machine. (Aug 10' one leaf with many of leaflets very pale yellow, though cooler House.)

(Aug 12th 8º let the leaf free— many leaflets much injured

 — 13th many leaflets very pale, some a little browned.