A

Robinia pseudo-acacia 1877

Aug. 31st

Syringed leaf with horizontal leaflets chiefly from below so as not to depress leaves, but sometimes along primary peduncle petiole with a few drops on surface with water at 58°, during 3' & only 2 leaflets were depressed.—

After an interval of about 1/4 of hour, syringed same leaf in same manner & for same time with water at 89° - 90°, & in a few minutes all the leaflets were depressed to angle of about 45° below horizon, so that opposite leaflets of about 90° together.—

I then selected another & rather older leaf with quite horizontal leaflets & syringed in same manner & time with water at 87° - 86°; after 5' - 6' the leaflet had fallen about 40° degrees below horizon.

(B

Robinia pseudo-acacia

1877 Sept I. Immersed for 3' in water at 53° F an older leaf with horizontal leaflets, & after at time waved it about most gently, not so much as a very light breeze — never once violently shaken— then After an interval of 10' to 15', the opposite leaflets were most of them at about an angle of 129° together beneath instead of 180; so that each leaflet had fallen 25° 30' degrees. This leaf was then submerged for 3' in same manner in water 86°-85° F & the leaflets now stood formed together an angle of 122° 30', so that each leaflet fell 3° 15' more.

[in margin:] White wool

(A younger leaf just above with horizontal leaflets was similarly submerged & treated & the leaflets after the interval stood at formed together an angle of 123°. 30 so that each leaflet had fallen 28°. 30'. This leaf was then submerged in the same warm water as above & now the opposite leaflet, (though with much variability)— formed an angle of 91° 30', so that each leaflet had fallen 44°. 15'; thus showing much greater power of the warm water in case of young leaf.

(C

Robinia

Black wool

A third young leaf with horizontal leaflets which had not been submerged in cold water was submerged for 3' in water at 85° F.; after an interval of 10' - 15' most of the leaflets formed together, an angle of 94°, so that each had fallen 43°; & here again we have evidence of greater action of warm water.

I suppose leaves get accustomed to long-continued cold rain & do not sink.

(N.B In all these cases immersion with slight waving for 3' in water at 85° removed much of silver, & the leaves when taken out, especially the younger ones, were much wetted & cohered, so as to be troublesome to separate.)

Sept 3d marked yellow wool put a leaf under dripping pipe 9 inches above leaf — large drops, at 9° 20' with water at 56°, but the drip hit only single pair of leaflet —

Leaflets slightly depressed. At 12° 12' dripped with water at 86°, this wet the leaves, but apparently did not cause any greater depression.— 4° P.m. (other leaves not in the least

[168bv]

asleep) the leaflets on which tepid water has dripped now stand at 90° together, so that they have greatly declined since they were dropped with cold water, whereas they were declined far less than 45° beneath horizon.)

D

Robinia 1877

Sept 5th

A leaf, standing little above horizontal with leaflets horizontal was placed under a jet with drops much closer closer than any rain & as large as [illeg] which threw up water, rain falling from height of 7 inches. — The water was at first 54° 1/2°, but rose after 1 hour to 66°. The whole leaf was beaten down to below ∟ of 45° with horizon but the leaflets remained for a long time horizontal; at close after shaking off drops the opposite leaflets stood about angle of 111° with each other, measured on under side.

At 10°. '15, after leaf had recovered & leaflets were horizontal, the jet was set into action with water at 87, falling after 1 hour to 85°. The jet was continued until 11° 30', but the leaflets did not become at all depressed!

Were they incapable of acting so soon again?

I do not understand case.— Had they been injured by long jet of water at first cold? I suppose not as they became horizontal after the cold water.

(E

Rob Robinia 1877

Sept 6th

Put leaf with leaflets horizontal (purple w.) under jet as before with w. at 85°-86° from 9° 8' to 10° 40' with no marked effect for some time, but in 20' slight depression, but at close but on shaking leaf slightly so that all drops fell off the leaflets stood at ∟ of 125° on under side to each other. No doubt the mechanical depression of whole leaf by the jet & depressed leaflets aid water in kicking off & it is remarkable that after this long jet with water at above temp almost all leaflets quite dry.—

Th took another leaf (black & white w.) (which had its bloom removed) & placed for 27' under jet at 85° no change in position of leaflets, when shaken leaflets horizontal! — No rain in temperate countries wd be above 85°-86°.—

The trees is not growing vigorous & not healthy second leaves, small, after potting. (Can this be cause?

F

Robinia

Sept 7'

Exposed full-grown leaf to jet of 87°-85° for 11' one pair which was before horizontal beca formed an angle of 104° on under side together ie. each had fallen 38° degrees. But another pair formed together only angle of 131°, so had fallen much less.—

I then syringed more placed same leaf so that it was struck much more violently by the jet, for 6 or 7 minutes & water was at 92°, & 2 or 3 pairs of leaflets, each formed angle on under side of 93° 93°, so each had fallen 43° 1/2 degree.

On the whole I doubt whether warm or cold water makes much difference, & I doubt still more whether the movement is protection against water logging on leaflets.