RECORD: Darwin, C. R. [1878]. Radicles of Peas (with diagrams). CUL-DAR209.5.132-139. (John van Wyhe ed., 2002-. The Complete Work of Charles Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Prepared and edited by John van Wyhe. 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).


132

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1878 Radicles of Peas

May 24 Several with pins through [sketch]— Radicles of 11 almost perfectly straight — several about .6 of inch   little more or less in length, some much shorter, but 4 had withdrawn part or even almost all of outer root, which is very tough, & the friction of edge had caused these 4 grew very oddly curved— One of the 4 was a very pretty case for skin had made it grew rectangularly & it had thus come into contact with pin, & this caused it to bend at rt angle in another direction. Therefore proved sensitive to touch above apex, & this kind of sensitiveness act on perpendicular radicle. I pinned 3/4 of them in new direction to see whether tip will now that freed from coat grow straight down. This case of effects of skin agrees with what Haberlandt says, though I never saw any such effect in the var. on which I (illegible) experimented viz.

See Back of p 5̲

I fixed with pins 15 Peas. & then put on square of sand-paper & shell-lac at 5º P.m. by 10º 30' P.m. almost all slightly bent from shell-lac, & one or 2 even nearly at right angles but by next morning 8º a.m (ie after 15º almost all straight, & several had reached support. They must be suspended.

133

(4

1878      Peas Radicles    Yorkshire Hero var.

 Thin   & Thick Paper

May 31' 10º 30' a.m. 10 Peas with thick sand-paper & thin paper on opposite sides, as nearly as possible (4º 45' P.m  No effect.)

(A) June 1' 7º 45' a.m distinctly bent from thick sand paper ✔

after 21º

(B) June 1 7º. 45 a.m like A but not so much bent     do ✔ O ?

(C) June 1' 7º 45' terminal portion of R. straight, but whole bent slightly from card thick card

D June 1. 7º 50' what very little deflection there is, is from thick card   ✔

4º. 45 rather more deflection in same direction (after 9º addition Hours

E (O)

F do.   curved independently of either square of paper  Opposed case

(G) do very slightly deflected from thick card .(Jun 2d 8º considerably deflected)

after 48º ✔   

H   do. straight   O

133v

(I) June 1' 8º a.m. — bent from gabel formed of 2 square, & rather more from thin than thick    Bent from gabel

(K) (do) straight   O

(L) (O)  Jun 1' 4º 45' no essential difference in any of the specimens.

(M.) bent more from thin than thick. Opposed

June 1' 8º a.m 10 Peas tried, I believe the bending is chiefly influenced by the square which is first put on, as this presses most on apex — On whole no trustworthy evidence

134v

(5

Peas Radicles of

May 31' 10º 45' 6 Peas with radicles horizontal & sand-paper affixed in opposition to geotropism.

4º 45' P.m (I) (II) & (VI) a little bent down by Geotropis,

(I) June 1' 8º a.m., bent down almost perpendicularly, but except terminal portion which is only inclined as if checked by card (4º 30" terminal portion perpendicularly down.) (Jun 2d 8º a.m do) Geotropism conquered from the first but slowly

1

Geotropism rather slight at first & then irritation

(II) June 1' 8º. a.m.(do) Hooked like skel. & raised above horizon

4º 30' almost a loop

2

24 (+) 21 (=)

   June 2d 8º a .m now the skin aft 45º

[sketch] 

 

Irritation conquered at first

(III) June 1st 8º a.m. do almost Horizontal but bent from card laterally 4º 30' terminal portion obeying geotropism June 2d 8º a.m. do

3

{ Irritating conquer at first

IV June 1' 8º a.m  bent down perpendicularly at angle of about 45º, Geotropism conquered but also pushed to ones side

4º 30' terminal portion much more perpendicular

4

[sketch]

June 2d 8º am

[sketch]

(This a sqr)

134v

(V) June 1' 8º a.m (V.) bent down perpendicularly (4º 30' do)

(5) see last page

Geotropism conquered from the first

geotropism acted aft 8ºslighly irritation conquered for short time & soon geotropism 

(VI.) June 1'. 8º am do. strangely contorted & raised above horizontal plane

[sketch]

(4º 30' terminal portion bent down almost perpendicularly)

[sketch]

(6)

There can be no doubt that sand-paper act on radicles extended horizontally as II. & VI raised above horizon. & III retained horizontal position; 2 others slight deflected from normal perpendicular course. In the 2 first case II & VI, a strange struggle has gone on between effects of card & Geotropism.

(out of the 30 Peas soaked at this time, the radicles of 3d could not escape out of skin & were much crumpled up;— at least 4 were clearly bent to one side owing to rubbing of portion of skin on one side, the other approximately straight downwards.)   

Effects of Skin

Allude to beans— How twelve 13 Peas the same manner & result very curious, showing that in case of pea irritation more powerful powerful, so that struggle between two kinds of action. the effect of geotropism acts at this age & irritation from card

135

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1878

Radicles of Peas

June 1. 8º 40' affixed with shell-lac square of sand-paper to tips of 8 7 moderately straight radicle— when a little bent to one side, the squares always put in opposition to existing flexure.

(1) 4º 40' a little bent from card

(2) (June 2d. 8º 30' no effect all straight none of these trials trustworthy)

(3) 4º 40 bent from card, but coincide with Sachs

after 8ºony 3 little bent & after 24º all straight

(4) card dropped off

(5) 4º 40 bent a little from card

(6) 4º 40 bent from card little much, but partly coincide with Sachs curvature

(7) 4º. 40' perhaps bent from card straight

lll/13

(8) 4º 40 straight

135v

decidedly    straight    doubtfully

 3/13   2/13   7/13   1/13 

136

(7

    June 4' 8º 50' Peas Radicles

9º Temp 58º. Passage dark

10 Peas with radicles with square of sand-paper on one side of apex— shell-lac.

5º P.m. 60ºF

(1) 4h. 50' bent a little laterally (June 5'. 8º am do) ✔ 1

(.2) (do.) bent a little laterally (Jun 5 8º a.m considerably deflected from card) ✔

(3) (do) bent slightly laterally (5th do slightly) ✔ 2

(4) (do) bent a trace (5th do quite straight)    ?

(5) (do) bent a trace laterally (5th do quit straight)    ?

(6) (do) not affected (5. do not affected, grown out horizontally, appears not to be geotropic

Monster

(7) (do) not affected (5' do not affected) 5º P.m. apex geotropic 5º P.m bent from card, but coinciding with Sachs curvature

O

(8) (do) bent to card (5th do bent to side of Card, but is growing abnormally close round seed.. 5º P.m apex geotropic

monstrous

over

136v

(9) 4º 45' bent a little from card (5th 8º a.m straight.) ✔

(10) (do) card loose Not affected, refixed square (5th 8º a.m. bent from card.) 5º P.m. quite straight    ✔

137

(8

Peas Radicles

June 11' 8º 45. 13 radicles, (nice & straight.) with square of sand-paper & shell-lac.— they had grown in water pinned to cork with peas themselves not immersed. Placed on chimney-piece in study.

Temp.   F 

  9. 30' am 68º 

 11. 30'  ⎯  68 1/2 

   72º   2. 30 

    72º   4. 15 

12th    

   8º 30' a.m 71º 

4º  ⎯  75      

(1) 4º 20' P.m slightly turned from card. (12th 8º 15' a.m bent from card at   abut 45º  ✔

(2) 4º 20' P.m. perhaps a little bent from card (12' 8º 15' a.m slightly   deflected certainly. ✔

(3) 4º 20' P.m. perhaps slight bent from C.) (12º 8º 15' a.m quit   straight  O

(4) 12th 8º 15' a.m slightly bent to   card-side.)  O

(5) 4º 20 P.m slightly bent from. C. (12th 8º 15' am slightly but decidedly bent from card.) ✔

(6) 4º 20' P.m pretty plainly bent from C. (12º 8º 20' a.m bent from card &   upward at above 45º. ✔

137v

Peas

(7) 11th. 4º: 20' P.m straight (12th 8º 20' a.m do .or straight   O

  (8) 4º 20' P.m straight (12' 8º 20 a.m do.  O

(9) 4º. 20' P.m straight. (12th 8º 20' a.m do curved to Sachs greatly, with tip to card (12th. 4º. 30' P.m. I doubt, I think tip bent partly from card, for otherwise wd have pointed to centre of earth to  doubtful case    ?

[sketch]

(10) 4º 20' P.m straight (12th  8º 20' a.m straight   O

(11) 4º 20' P.m turned chiefly from card (12th 8º 20' a.m curved nearly 45º from card &    geotropism  ✔

(12) 4º 20' P.m. straight (12th 8º 25' a.m, slightly curved from card; straight 4º 30' card detached.)O

(13) 4º 20' P.m straight. (12º 8º 25' curved at nearly 45' from card.; 4º 30' P.m. bent at right angles.    ✔

4º 30' P.m Fixed five card to 3, 7, 8, 5 10, & 12, (June 13th 8º am. no effect, 4º 45 do shows that very long roots not sensitive) some card washed off Jun 14th 8º a.m. No 12 now deflected from card

138

(9

Peas: Radicles of

   very young ones Kept at temp

July 12' 8º 30' a.m sqr. of sand-paper fixed to 11 radicles, mostly very young ( germinated on sand in study see upstairs cool weather — jar placed in cellar close to ice-box, with small lump of ice in water at bottom. Temp of air close to jar at 4º 30' 14 1/3º 5 C = 58º 56º F

(4º 40' I think some acted on no clear effect) (18th 8º 30 Temp 13 2/3 C) (14th 7º 30' a.m 13º 1/3 F C)

 

(14th put into ice-box)

  card fell off 

(1) 4º 45 refixed sqr with canada shellac. (14th. 8º a m no effect) 8º card knocked off put on glass & asphalte (15th 7º.45 decidedly curved from glass.) now in ice-box (16th 7º 30' do)

     O

(2) (14th 8º am no effect) (15th 7º 45 slightly inclined from sq.) in ice-box (16th 7º 30 do) (17th 8º decidedly inclined from sq

     O

(3) (14th 8º a.m no effect) (15th. 7º 45 no effect) 16th 7º 30' do (17' 8 do)

      O

(4) 13' 8º 45 sq fallen, refixed it (14th 8 no effect) (15' 8º. do) (16th 8º do) (17th do)

(5) 14th 8º a.m curved to Sachs & from sqr (15th 8º do in very conspicuous manner)

(6) 13th 8º 45 Curved at right angle, sq. loose I know notnot whether effect — refixd sq 14' 8' seem as if curved from glass —(15th 8 I think has been affected) (16th 7º 30 straight down) 17th do

(7) 13' 8º 45 I think a little curved glass from Sq. (14th 8º no effect) (15th 8º do) 16th do 17th do (17th 7º 50' am new sq) root very long Kept on tray very warm. 18th 8º. a.m. not the least effect

W

over

138v

Peas Radicles

W  

(8) (14th 8º no effect) (15th 8º do) (17th. 7º 50' new sq kept on tray very warm) root very long & straight 18th 8º a.m not the least effect.)

W 

(9) 14th 8º no effect (15' 8º do) (17th 7º 50' new sqr) Kept on tray very warm root very long & straight 18th 8º a.m not the least effect

(10) 14' 8º no effect (15th 8º decidedly curved from sq)in ice-box (16th 7º 30' do

(11) 14' 8º no effect (15th 8º decidedly but slightly curved from sq) in ice-box 16th 7º. 30' do (17th plainly curved from sq.)

(Put into ice-box. (15th 8º a.m left on Study Table Temp about 65º F

(16th 7º 30 put on sand-bath. Warm place.

Here we have same evidence as in former paper that radicles more sensitive when kept in very low temp than when kept warm.— I wonder what temperature the Peas were exposed to, not in the old experiment when George made drawing & the radicles acted so well.— I guess best temp. 45º— 4 50º

7. 8 & 9 4º 45 no effect 17th

139

(10

Peas — Radicles (very cold)

July 12' 8º a.m sqr of sand paper fixed to 9 radicles (as below) mostly very young — germinated on wet sand in study - cool weather see upstairs for Tem.) — jar placed in ice-box, with small lump of ice in water. Temp. within of Box, close to jar at 4º 30' P.m. 44ºF & I think some have acted on by sqr (Temp. 13th 8º 30' a.m 44º F (15th Temp 14th 45º 1/2 F.  7º 30 47º) The radicles have grown very slowly .N.B. 

(1) 13th 8º 30' a trace curved from sq glass (14th 7º 45' certainly a little curved  17th 7º 30 20º or 30'  from the vertical & sq    ✔

(2) 13' 8º 30' a little curved from sq (14' 7º 45 a little curved from sqr) (17th 8º considerably deflected from side on which I believe sq was but dropped off       ✔

      ✔

(3) 13th 8º .30' decidedly curved from sq, but perhaps affected by skin (14th 7º 45 a little curved from sq (17th 8 quit straight       ✔

(4) 13' 8º 30' decidedly curved from sq (14th 7º 55 I do n no effect 17th 8º decidedly deflected from sqr

    ✔

(5) 13º 8º 30' decided curve from sqr (14th 8º decidedly curved inclined from sq, but to S. (17th 8º now Straight.) O

(6) 13' 8º 30' I think no effect grew out horizontally at first (14th 8º no effect, but sq. on summit at rt angle 15' 4º 30' apex now bent down at right angles from course card decided effect; card has been fixed with asphalte since original attachment of squares             ✔

(7) 13º 8º 30 perhaps a shad curved from sq (14th 8º decidedly bent at 45º fr sq (17th 8º now straight: put fresh sq. on.— squ. dropped off 18th:

over

139v

Peas Radicles

O

(8) 13' 8º 30 no effect (14th 8º no effect) (15th 4º. 30 now curved a little from sqr (17th 8º straight)

          O

(9) 13' 8º 30' no effect (14' 8º no effect.) (17th 8 do)

6/9

14th 7º 45' a.m Temp of ice-box 45º 1/2 F

(15th 7º 30' a.m The radicles have now grown to a very fair length though Kept all the time in ice box but there are no striking cases of curvature — no evidence worth anything — Changed water & left on study Table Temp about 65ºF

(16th 7º. 30 all the radicles (except one) remarkably straight placed on middle & warmer place on sand-Tray)

18th no effect produced on those which retained their squares.— It seem that more effect was produced at the very low temperature viz 44º—47º, than at high— indeed none what ever when the seeds were kept on tray when sand from about 72º to 85º.  

12 radicles


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

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