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Nov. 30' 1878

Oxalis sensitiva. Seedlings

(Seedlings in Hot Case.)

Petiole very short with conspicuous pulvinus.—

At noon Cots. horizontal, I irritated them & they quickly closed to angle of less than 90°— When I looked at 4° 5' almost closed at 4° 30' quite closed by rising up.— So sleeps & movement the reverse of true leaves.—

Dec. 1st at 12° 18' irritated both Cots & there pulvini during 30" with thin split bristle, & in 2' Cots, plainly raised: in 10' after commencement of rubbing cots, instead of forming∠ of 180° together formed angle of 84°, so each had risen 48°. When looked at again 35' after first rubbing each had risen 52°.— When looked at again after an interval from the last observation of 63' they were again horizontal. The were pot was then carried on tray, & I do not think much shaken, but when these Cots had risen considerably. At 2° 1' put into dark cupboard in Study & after 26' almost shut & so remained for another hour, & did not open when placed in N.E window at 2° 45'.— Are they sensitive to slight darkness? — The rising in dark may have been caused by after effects of the shaking.— (over)

[in margin:] From experiments on 2d there can hardly be a doubt that the closing due to darkness

[1v]

Dec. 9th seedling almost a week 8 days old, with plumule just first true leaf just developing— petiole of Cot. very short, consisting of mainly of strongly developed colourless pulvinus, which 2/3 of length of petiole— strongly convex on upper side & more fully there developed.—

I may say that 2/3 of short petiole consists of the pulvinus. — Hypocotyl covered with down-curved hairs & some viscid glands as a protection of upwardly crawling enemies—

say— Pulvinus very strongly developed; formed of small cells.

What a contrast with Ox. corniculata & still more with tropaeoides!

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Oxalis sensitiva

Dec. 2d noon jarred pot with 2 seedings with Horizontal Cots holding in pot Hand, with short stick about as thick as my thumb by hitting it rapidly during 1'.: in 9' afterwards cotyledons plainly raised considerably.—

Eleven minutes from the first jarring I banged pot up & down on wooden floor during 30" & then left it for exactly 30' or 1/2 hour for I expected that this wd have increased the closing & on my return the Cots. of both seedlings had become quite Horizontal! So that jarring + banging produces very temporary closing It looks as if banging pot bottom of pot did not act so well as the jarring on side with stick.—

Seedlings with cots of Mimosa pudica (not Dionæa) not affected by the rapping of pot in exactly the same manner.— (First true leaves very little sensitive—

[2v]

Dec. 15' 10° P.m seedling born on Nov. 29th now has a true leaf with only 2 leaflets, & this closely joined & depressed, whilst the 2 Cots are raised & closed, as far as petiole in middle will permit— This petiole raised— So Cots. sleep for at least 17 days.

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