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Mimosa albida

Nov. 24. Plant in case temp. 81° rose to 86° during observation, but in latter part fell to 83°— say average 83°-84°.

I observed as tips of 2 terminal leaflets on same pinna of lower leaf, which was turned directly from the front of Hut & chief source of light which is the most sensitive one of the few on the plant— full-grown good leaf— painted Marks were placed & flat glass several inches above. Observation commenced at 10° 27' & finished at 3° 10, lasting for 4h 50m. Day generally cloudy with gleams of sunshine.

The movements did not seem at all directed by light, the first movements in both leaflets being to the westwards

Eleven points were marked on glass.— The earlier one at very short intervals. (see back) the later ones at longer intervals— So that course no doubt more complicated than that represented on Diagram (see back)—

Leaf A made, as traced 2 very unequal irregular circular elliptical figure in the 4° 50', but one was completed in 58m. Leaf B made a horse-shoe, i.e. almost a

[7v]

Times of Observation

[times not transcribed]

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M albida

complete circle in 1h 7m— Then a second minute circle, & then moved, as did other leaf to East, ie opposed to course of sun. It is evident movement much slower & less than in M. pudica.— Probably from the movement being to a certain extent continuous, the main petiole, moves; but there is quite enough independent movement to show that the sub-petiole of the 2 opposite leaflets on the same pinna move independently.—

I also observed the little basal leaflets on 2 leaves they have extremely slight movements (& yet go to sleep) & their relative position, judging by eye did not alter whole day— I observed one by glass Plate & mark & it lip certainly made an excessively small circle; but it may have been solely carried by movement of main petiole— Certainly do not move more, if so much as the large leaflet; so differ much from those of Desmodium

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M. albida

Nov. 26 Put on large drops of water on 2 terminal leaflets of old full-grown leaf (on side of label) (having first washed away wax with water & soft brush at 95°). I also washed 3d L. on same side & 2 terminal leaflet on other pinna other leaves to see if this process injures leaves. Put on at 8° 40' & removed in 27' at 12° 15— but each leaf was dry for interval.

The leaflets were pinned down with fine needles.

I removed water & evaporated it on platina, (not good plan,) & perhaps there was little more matter in minute cakes left, than from the water on platina foil, left for same time exposed. This collects a surprising quantity of dust & matter.

I suspect leaves too old, like case of M. pudica.— Temp during experiment of Case generally about 82°-83°, rising at night to 96°.

(Nov. 28° 12° 30', no discolouration.) (Dec. 9th no discoloration)

(N.B. The little basal leaflets are often either one or both aborted, in my plants)

(Dec. 9th. on touching leaf I clearly observed little leaflets moving as quickly as big ones.)

(Dec. 7th Lett. found main petiole at 6 A.m, quite as upright as during day, but there was moonlight— plant not fully awake

(9 (10

M. albida

Nov. 26' I observed angle of 2 uppermost main petioles at 4°-5' P.m. & with the perpendicular they were both about 54°.— At 9° 30' P.m. the one had sunk to 81° with perpendicular, so had sunk 27°; the other was in nearly same position. [sketch]

Case very warm.— This makes me believe that during sleep main petioles of young & vigorous leaves wd become depressed greatly.—

Dec. 1. 12° Quite young leaves a mere puff or little blowing from mouth cause leaves leaflets quickly to shut, but though I blew for some time not one shut quite closely— The convergence of the 2 pinnae rapid & conspicuous.—

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M. albida

Dec. 5. when very young & sensitive leaves have large drops placed very quickly on them, not affected. When dropped from height leaves instantly slope & then drop off beautifully. Important, (marked with (upper of 2 young leaves above bits of card.))

Dec. 5 at 8° 25' put on large drop of pure water on 2 nearest terminal leaflets of young but full-sized leaf, or nearly so, having first washed off bloom with very soft camel & water at 95°-94°— I also washed a 3d leaf next beyond the 2 terminals.

Water was renewed & left on fo until Dec. 6. 12° 30'; but these leaves were dry for good hour or 2 in interval. Case during most of time only moderately hot, viz 80° to 85°.— sometimes 90°.—

Dec. 9th no effect produced by these drops.

No sunshine if leaves are not injured probably due to absence of bright light. more light & chlorophyll.

(N.B. old leaves formerly tried never affected in the least by the drops.)

I evaporated water from the 2 leaves, & it did not leave more residue than the same water on other occasions exposed to dust; but the rims of water were pale dirty greenish brown, which I have not seen from the pure water.—

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M. albida

Dec 5th  I observed 4°. 5' P.m main petioles f of young leaves formed very high angle, less than 45° with vertical stems above, — & at night 9° 30' they had not sunk, or sunk very little— Yet when leaves, asleep were pinched main petiole sunk, like M. pudica.— This not sinking, at least at first, shows how different movement from touch or syringing.

Dec. 10. Lett. observed a 2d time at 5° 30' A.m. & petioles not depressed; but there was moonlight.—

[text excised]

N.B. Sun., though hot, has little actinic power during the winter?? & its duration during the day short

Dec. 9th 9° 30' put on drops of one leaflet which had been previously washed on previous day, Dec. 11th & left on for whole short day; sun so hot that (after long cloudy weather) plant drooped a little, & had to be shaded.

But on Dec. 11th 12° no effect, or very doubtful shade of yellow cd be perceived.— I at same time I put on drops on 3 other leaflets not washed & they remained on all day, but have produced no effect.

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M. albida

Dec. 11th  12° — Leaf with red wool, angle of petiole (with the vertical above) 71°; divergence of the 2 pinnæ 89°

I then hit the leaf with one finger & pinched it for 45s & the angles of petiole was now 90° (so had fallen 19°) & the divergence of the 2 pinnæ 49 1/2° so they had converged 39 1/2° The leaflet closed greatly, but not quite shut; & as we see the 2 pinnæ were a long way from shut, so not nearly so much effect change as during sleep. I now syringed this same leaf for about 45s with the finest glass syringe, but the petiole did not fall hardly sensibly more for the angle was 91°, but the divergence of pinnæ was only 32°1/2 so that after shaking they again converged 17° so we see that water produces more effect than touching; but I think leaflets were more frequently & perhaps more agitated by the syringing than by the touching. The former case of the old & to leaves gives better evidence of water producing a greater effect than touching—

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M. albida

Dec. 11. I then tried another leaf, close by & equally young which had petiole with vertical at angle of 54 1/2° & 2 pinnæ diverging at angle of 81°.— I now syringed (without any previous touching) for about 45s, & the petiole fall to 72 1/2 with the vertical above; so it fell 18° (ie nearly as much as in last experiment viz 19°); & the two pinnæ now diverged only 44 1/2°, so that they had converged 36 1/2°.— The leaflets in this b case did not close nearly so much as the last,— in fact I never saw them close nearly so much as in the last case. —

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All these movements are double of what I said for I used the 1/100 micrometer, each division of which = 1/500 {

The little leaflets do not apparently move so quickly as the large ones. — ←

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M. albida

Dec 14th

11° to 1° & 2° 30'.—  Frank & I have been watching spont. movement of large terminal leaflets under compound— (2 inch with tube down at 2 inches & weak eye piece & 1/100 micrometer). The movement is insensible, but not very slow viz in one stance 10/1000 10/500 of an inch in under 3m. The tip of leaf continually moves up & down out of focus.

There is another strange movement, viz leaflets whilst keeping in focus & not moving laterally protrude & shorter thrash, certainly by as much as to 1/100th of an inch.

I can understand this only by supposing that main petiole moves up & down, & the pinnæ move in opposite direction up or down, so as to keep on the same horizontal plane, & get to shoot forward forwards from the axis, or backwards to it.

I also observed terminal spikes of the 2 little leaflets, together in the field, they moved very slowly & insensibly insensibly to right or left,, & which probably was caused by movement of whole leaf— but one sometime moved independently of the other; so that the 2 spikes sometime approached by 2 or 3/1000 of inch & recede from each other. I clearly saw also the protruding & retracting movement, whilst keeping in focus. The spike of one became out of focus, whilst the other did not. One moved laterally whilst the other was still, so that the little leaflets certainly move independently of each other, or it may be the pinnæ independently of each other; but probably little leaflets. It appeared appeared as if the lateral, up & down, & protruding, movements, were not consistent, but replaced each other

[69v]

Lettington looked again & the main petioles were not depressed very early in morning before daylight in winter

April 4'. 1874. Boys have observed 9° 45' P.m. the main petioles not depressed.