RECORD: Darwin, C. R. 1878.04.25-06.11. Radicles of Radishes. CUL-DAR209.5.193-195. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)
REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 5.2023. 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-DAR209.5 contains materials for Darwin's book Movement in plants (1880).
(1
Radishes radicles with bits of sand-paper very small with shell-lac to tips off
All affixed at Ap. 25th 5° P.m
8° 15' a.m Ap 26th
(1) decidedly curved more than right-angles from card & from gravity ✔
(2) curved at right-angles to gravity, but cannot be said to be curved from card. O
(3) short radicle I think not affected O
So difficult to fix them & grow irregularly & seem to turn up to damp— cork lid in the [illeg] of
(4) perhaps very slightly curved from card /
(5) whole root slopes from card /
(6) completely Hooked from card, rather large piece of card ✔
(7) quite straight O
(8) a little sloped from card.
Two splendid cases — 2 not affected — other 4 doubtfully sloping from card.—
(2
Radicles of Radishes.
May 25' 5° 15' P.m seeds on zinc plate with Holes; bad plan for radicles often touched edge & curled up at right angles under plate, showing apparently irritable— Several grew nearly straight.
5° 15' P.m affixed with shell-lac square of sand paper of various sizes to apices of 10 Radicles.—
My 26' 8° a.m. I can see no clear effect. 2 or 3 with tips bent to Card — one or two from card — one bent at right angle irrespectively of position of card & of irritation from zinc Plate
The Zinc Plate a very bad plan—
27th I am now well convinced that radicles turn up to damp zinc Plate, nearly all have turned up— cards hardly any or no effect— I doubt now about edges of zinc irritating root
(3
Radishes, Radicles
Jun 8th 7° 50' a fresh set if 12 radicles, all except (3) contorted & unhealthy, fixed large piece of sand-paper with thick gum on them.
9th 8° 15 so contorted, can tell nothing, I think act
Jun 11' 9°. 15 6 radicles with square of sand-paper & shell-lac
Seeds germinated in water pinned to cork; many crooked, & the best grown had grown out horizontally, in water as if geotropism did not act in water!! An almost useless trial this— mostly rather large squares of sand-paper.—
4°. 30' P.m. 3 long radicles placed in air, damp are now upturned from gravity so as to touch the cork above.
12th 8° 30' am, another long radicle bowed up to cork-roof; the tips of other are now beginning to obey geotropism.— one not affected; another slightly— The remainder of seeds on the cork to which cards not attached have grown very crooked & are more or less monstrous.— Certainly this case indicates, as far as can be trusted, that tips are sensitive.
Consider all evidence
[195v]
Radicles of radishes
1878 June 7 6th 8a 12 radicles with sand-paper & shell lac on tips on dry cork. in passage. — many crooked radicle thrown away.— 4° 30' P.m. 2 of the r. excessively contorted, but I can see no evidence of bending from squares.
7th 8' a.m (1) (2) (3) a little turned from card
8th 8° a.m (1) now straight (2) bowed toward card. (3) bowed from card.
(4) (5) do not turned (5) 5° 15' P.m is now turned from card
(4) 5° 15 still straight
June 8th 8° a.m. still straight (5) 8th 8° a.m much bowed from card
(6) do Hooked upwards from card (removed) [sketch]
(7) do straight (left) (5° 15 still straight.) 8th. 8° a.m still straight.
(8) whole radicle inclined from card → [sketch]
(9) straight slightly inclined from card (left) (5°. 15' still inclined) 8th 8° a.m still slight inclined from card
10 greatly contorted, but whether from action of card doubtful [sketch]
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 27 July, 2023