RECORD: Darwin, C. R. 1878.02.15-12.31. Acacia retinoides. CUL-DAR67.53. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 3.2023. RN1

NOTE: See record in the Darwin Online manuscript catalogue, enter its Identifier here. Reproduced with permission of the Syndics of Cambridge University Library and William Huxley Darwin.

The volume CUL-DAR67 contains notes on 'bloom'. Francis Darwin explained: "His researches into the meaning of the 'bloom,' or waxy coating found on many leaves, was one of those inquiries which remained unfinished at the time of his death. He amassed a quantity of notes on the subject". LL3: 339. See an Introduction to these folders by Christine Chua & John van Wyhe.


[53]

Acacia retinoides 4 Phyllodia sponged both surface with tepid water both surfaces & marked with black wool — on 3 main branches. Feb. 15. 1878 8˚ a.m.

Recleaned both surfaces May 20th no effect. — Phyllodia are silvery both surface in water before they were sponged — Kept in greenhouse— growing vigorously

July 11th 8˚ a.m.

"Green wool Branch" — leaf with black wool, whole of lower surface up to apex thickly dotted with black smut — 2 or 3 dots on upper surface— stem all round round base of leaf (but not on opposite side) brown & this side could not have failed to have been sponged. The b phyllodium next beneath has about 1/3 of b basal lower surface spotted, & this was so clear could hardly have failed to have been sponged.

July 21' The leaf is now withered, & must have dropped off 2 or 3 days ago, for hung by mere filament — not one leaf with white thread, above or below, had dropped. —

"Red Wool Branch" Black wool leaf whole lower surface dotted with smut. — stem brown & dotted with smut, all round but especially on side of leaf. — Of leaves above, the 5', 6' & 7th alone in part yellowish & here dotted— Of leaves below none affected except a single spot on 2d below.

(Aug 30th a leaf high up on this branch, not marked with white thread fell off today, & others afterwards fell off.

Oct 9th one with white thread fell off, so before black or cleaned one.

[53v]

Thus 3 above, & 4 below

I know that the black-wool fell off a long time before any white

"Now Yellow or Green Wool" (it dropped July 18th 19' or [illeg])

Sept 30th a white thread leaf fell off — Oct 9th two white threads fell off.

Nov. 10th a white Thread dropped off.

― 18th do. do. do. do

Red W. Branch.

Nov. 8th leaf with white thread dropped

10th leaf with Black wool dropped.

17th leaf with white thread dropped

N. B From some unknown case a vast large number of leaves dropped off this branch above the group of white thread & black wool, & as the 2 or 3 white threads which dropped off before black wool, were upper ones— This case not so hostile as it appears.

[53b]

(Brown w. Branch) Lower leaf with blue black w. — whole lower surface dotted & stem on side of this upper & black w. leaf — Of leaves below 2 badly affected yellowish & decaying — One leaf above between this & next black w. not affected

(Aug 29th this leaf has upper half almost dead & withered.

Sept 3d it came off with a touch — not one of marked leaves above or below as fallen, so 3 have now fallen & no others. —

on Brown w. Branch. 4 white threads above & 4 below & 1 intermediate.

Upper "black w. leaf" lower half of lower side much spotted — no leaf higher up affected. (Aug 5th this leaf is now yellow & will soon drop utterly different from all other leaves; in the evening fell off with a touch, none with white at all withered)

Brown wool Branch Sept 27th 1 white thread dropped —

Oct 3d. do. Oct 8. do.

[53bv]

Dec. 31st. End of year 1878

On Red W. Branch. 2 more white thread came off with slight pull, only one & that had been above black wool still adhered

Green Wool 3 with white thread still on

Brown wool 1 dropped with slight p pull; 4 still adhering, 2 above & 2 below the 2 blacks, & there was originally one between the 2 Blacks. —

N. B a vast considerably number of leaves on branch with red wool, fell off spontaneously above black wool, from some unknown cause. —

 


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Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)

File last updated 14 June, 2023