[100]

Mimosa pudica

June 1877

I must pin open leaf & use drops of water at 90° or 94°. 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 8° 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 90°.

Left leaf drops put on 8°  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 11° 30'— (Often left dry for a space so wd respire

July 14th 8° 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 10° 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 8° 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 12°— rubbed several leaflets with small & gentle camel-brush & water at 90°, 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   10° 45' cleaned the lower surfaces of 2 right-hand pinnæ on both sides with water at 90°, & 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' 9° 15  a leaf placed under the dripping machine. (Aug 10' one leaf with many of leaflets very pale yellow, though cooler House.)

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

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