[60]

Cassia Caliantha Horace

Down

Aug 10th 1877.

11. 20 A.M.

Tried the experiment of shaking for 2 minutes on an old leaf. (the same leaf that we tried on Aug 12th) and a very much younger one

[annotated sketch]

Before shaking A = 10° B = 44 1/2° C = 61°

After shaking A = 16 1/2° B = 44 1/2° C = 58°

Hence Old leaf went downwards 6 1/2° reducing the angle between stem and chord of petiole from 125 1/2° to 119°; and younger leaf went downwards (3°) reducing the angle between chord of petiole and the stem from 105 1/2° to 102 1/2°.

1

Down Aug 12th 1877.

2nd Experiment

Another experiment

Cassia Caliantha

We measured the ∠angles of petiole &c at 11. 30 AM, and then shook the plant for 2m rather violently & measured that the ∠ angles again; then syringed the leaf with water at about 85° F and measured angles again for 2 1/2 minutes about & shook it for 1/2 a minute, which shook very nearly all the water off, but one I saw a little sticking.

[annotated sketch]

The angles marked A & B was were

A before shaking = 12° B = 4 1/2

A after shaking = 16° = 43°

A after syringing = 21° = 41°

A asleep at 9. 30 PM = 27° = 44°

(2

The angle beneath or lower side between petiole & stem of plant below the leaf

below leaf.—

= B ─ A 180 ─ (A + B)

before shaking = 32 1/2° 180° - 56 1/2° = 123 1/2°

after — = 27° 180° - 59° = 121°

after syringing = 20° 180° - 62° = 118

asleep = 17° 180 - 71° = 109

Hence petiole moves down 5 1/2° 2 1/2° by shaking and after syringing it moved 7° 3° more downwards & sleep made it move 8° 9° more

This result is only approximate as the vertical plane in which the petiole appears to moves, does not also contain the stem of the plant, though it nearly does.

(3 2

Cassia.

The angle which the surface of leaflets made with the horizontal plane was

before shaking = 5°

after shaking = 62°

after syringing = 79°

asleep— = 0° 90°

The an angle which the surface of the leaflets made with petiole are

before shaking = +7° on one side [diagram]

after shaking = - 46° [diagram]

after syringing = - 58} on the other

asleep = in the same plane [diagram]

[diagrams]

(4

Cassia

[diagram] Plane of leaflet in which OA & OB represent mid ribs of two opposite leaflets. when not shaken.

OA = OB = length of 6th 7th leaflet from end

AB = distance between tips of pair of leaflets before shaking

AC = distance after shaking i.e B moves to C.

AD = … syringing i.e B has moved to D

Angle between centre ribs of leaflets

before shaking = 138°

after shaking = 59°

after syringing = 38°

Asleep = 0°

Hence shaking made centre ribs of leaflets approach 79°, syringing 21° more than shaking & sleep made them move through 38° well more, i.e till they touched

(5 (4

When asleep the leaflets always come face to face on the under side of the petiole — supposing the petiole to be nearly horizontal— except in the some cases when the leaflets near the base fold together so that the mid rips of the leaflets touch the petiole one on each side, one one or are make a small angle with it. The angle which the mid rib of the leaflets makes with the petiole is less at the base than at the point; and large near the point.

(6

When the leaves are shaken; the leaflets rotate on their mid-rib s; & the tips of the leaflets approach each other; and the line also approach the pet tip of the petiole; and the line & joining the ends of the mid ribs of the leaflets sinks below the petio petiole.