(1

Cotyledon

Lupinus luteus 1877

Horizontal glass

Oct 15. Stem secured; long bristle to 1 cot: traced on horizontal glass. From 8° to 11° 33' moved towards light, very slightly zig-zag: tracing not copied At 11°. 35' new dot—aga (see 1) very slightly zig-zag to 6° when went from light & moved very slightly zig-zag.

Next morning end of bristle out of range of glass. The zig-zagging when moving slowly makes me think slight nutation.

[in margin:] Leaf The 2 cots were oblique to light & tracing on horizontal glass

(Oct 16th new tracing, more magnified, of same plant in same position with stem secured to stick. Sed diagram (2) The plant had now grown accustomed to position & tracing shows how much it nutated; The gre but still affected by light. The great zig-zags in after mid-day (& at early night) was when sky became wonderfully dark. Though diagram (1) less magnified it certainly seem that nutation checked by Heliotropism.— Diagram (3) shows movement of same leaf traced in vertical glass from 3° to 5° 30, & here we see leaf cot. went up & down & rose greatly after 3. 58, so as at 5° 30' to be out of glass, but I ascertained roughly that it was still moving upwards from 8° 5' to 10° 30' P.m. Even to eye Cots. look more inclined at night, but not enough for protection.

I also gummed bristle to cot of another plantlet, free & traced (Diagram 4.) from 3° P.m to 10° 25 the movement, so that it seems to nutate a little. The movement from 5° 25 to 7°. 15 was in direction of light, though then quite dark.

(2

Oct 17th

Lupinus luteus

I selected a Cot: which from facing light stood vertical & thus was bad choice. I fixed bristle to its back & secured stem but next morning I found the stem loose, traced on vertical glass the bristle moved to N.W in horizontal line almost like (4) but with only a trace of zig-zag towards light.

The movement of same bristle was traced on horizontal glass (see Diagram 5) This seems to show that Cot first moved back or opened (for it had become well adapted to light), at the same time whole stem (as shown on vertical glass) moved to left or N.W; but the zigzag from 3° to 10° 30' P.m can be accounted for, only by cot. moving flapping or opening or shutting a little as it gradually rose or closed, or by lateral movement of Cot.

(3

1877

Lupinus luteus Used

To ascertain nutation of stem.

Oct 19th Fixed bristle on tip of stem close beneath Cots. & pin-Head [sketch] traced below & traced on horizontal glass. The plant bore 2 leaves not expanded just above with petioles 1 1/2 long. Tracing moderately much magnified. about 100 times, for glass to pin-head 10 inches & pin-head 1/10th of inch beneath end of Bristle.

See diagram (H. (1)) Traced from 7° 53' to 12° 59' & during this time clearly made travelled 4 times in one direction & 4 times in a nearly opposite one     But at first I was not at all aware how quickly it moved so diagram is really far more complex than appears, for observations were at first sometimes taken at interval of 3/4 or 1°, where they ought to have been taken every 10' or 15'. During above times plant kept quite dark, but at 1° cover taken off, but this made no difference in see Diagram (2.) & glass slided nutation, & point the point was traced to 10° 30' P.m. but late in evening only at longer intervals— During this time (at least 19 times) changed course 4 or times up or down.

It is evident that the axes of nutation change, as with Climbing Plants. The position next morning (20th) shown & nutation was evidently beginning. There can be no shadow of doubt that there is rapid nutation of stem with cotyledons & leaves developed as above described, but small in amount — The greatest distance from point to point being (as magnified 100 times) only very nearly 1/50th 1/60th of an inch.— (a) Back

The quickest rate of movement was nearly at rate of 1/50 1/60th of an inch per hour. The quickest apparent movement, being so magnified was 1.908 per hour, nearly 2 inches.

There was no evidence of heliotropism, yet young plants after some days have their stems bent to light & cotyledons also bend to light.

[3v]

(a) It cannot be doubted, small as the distances amt of movement viz 1/60th of an inch between extreme points that c no one can doubt that there was nutation, who will consider Diagram H. remembering that point wd really be further apart & the apparent rate of movement per hour. — If soil mark below had settled a little or bristle moved ever so little, this wd not account for the incessant & diversified movements.—

(4

Lupinus luteus

Oct 20' fixed stem securely & put bristle long to one Cot, which was inclined & faced light, traced on vertical glass not greatly magnified. Looked along bristle. in making the tracing see Diagram K. [sketch] Light

Cot. fell all day in zig-zag line, Sky bright uniformly & I think this proves that it must move laterally or nutate, at 7° 20 rose a trifle & remained near same spot till 10° 30'. Next morning was much lower. see Diagram K.

(Oct 21', freed the stem & put pot a little further off, so as to magnify more but made no other change & traced, by looking along bristle, on vertical glass. This was useless trial as whole stem moved so greatly to light, until 7° 30' P.m, when geotropism conquered effects of Heliotropism & rose a little till 10° 30' & during night rose rather more. The only interest in this diagram, compared with Diagram K is that it zig-zagged less, as I suppose Nutation of stem & leaves (if latter nutate) was converted into Heliotropism, which was conclusion formerly arrived at.—

(5

Lupinus luteus

Vertical glass

Diagram z.

Oct. 23d Plant kept dark, stem secured just before first dot was made. [sketch]

Bristles affixed longitudinally to each cot, projecting 1. 3/20 of an inch. From relative distance of glass, ends of bristles & marked behind, left-hand Tracing is magnified 20.2 times; & right-hand tracing magnified 13.6 times. The 2 Cots did not follow same course, partly due to direction of two points being somewhat different, & differently magnified; but they certainly did not follow exactly same course. Both become depressed during day & right hand one, (which was at first rather more depressed than other), bent down in so zig-zag a movement line, that it must be nutation nutation When it becomes After 5° P.m. movement very small. — Did not rise during night, probably probably due to plant having been kept dark all day— Nutation of stem already & freely proved & [rise] qu diurnal movement or rather nutation of Cotyledons; zigzag downward.

[insertion:] The diurnal movement is a modified circumnutation. From a few observations made between 8° & 10° a.m. downward movement commences at that time at last I measured distance of 2 tips of Bristles at 12°. 40' & again. at 5° 30' & at 8°. 45'; at these 2 latter times distance the same & rather greater than at first period, (see old paper of data) proving that Cots open a trace very little, but far too little to produce any visible effect or any service to the plant.