RECORD: Darwin, C. R. & Francis Darwin. [1874?].09.09-10.04. Dionaea. CUL-DAR59.1.22-24. (John van Wyhe ed., 2002-. The Complete Work of Charles Darwin Online, http://darwin-online.org.uk/)
REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 10.2022. 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 volumes CUL-DAR 54-61 contain material for Darwin's book Insectivorous plants (1875).
Dionaea muscipula is the Venus flytrap. These notes are for Darwin, C. R. 1875. Insectivorous plants. London: John Murray. (F1217)
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Sept 9th 8º 40' Dionaea
flat bit of dry neat & dry albumen on 2 leaves.
Sep 10 [illeg] 7 AM.
The bit of meat though so dry as to be brittle when put on, became very slightly damp during the night owing to the plant having been covered with a bell-glass, & consequently some bits had caused some acid secretion
(A bit of dried albumen continued still dry & had caused not a trace of secretion
Soaked the bit of albumen & placed it on blotting paper & replaced it in the leaf. also put on a bit of dry gelatine
Sept 10th At 4º 30; the albumen had caused much secretion, barely acid.
Sept. 11th 7º 30 A. m. To my great surprise the bit of albumen had caused the end of leaf on which it stood to partially close & when I ↘
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removed albumen but not the albuminous secretion leaf slowly closed. This very important — (albumen of good size) as bearing on slow closure of leaf round captured insect did not occur before. — (I marked this leaf with white Thread—to see when opens.)
it is curious that how little absorption must suffice viz meat slightly dampfrom bit being left on leaf under dry Bell-glass.
Sept 13th 8º Am the distal end began to open & now Sep 14' is much more open than the other end, where I believe the albumen had lain.
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Dionaea 1874
Sept 10' 7º 30' put bit of dry gelatine on leaf no effect after 24º — soaked it & put it Sept 11th at basal end of leaf 7º 45' Sept 11.) I plant under damp bell-glass —
I also placed at 5º P.m. Sept 10th last night on leaf on open plant (ie, not under Bell-Glass) a bit of dry meat, & this morning Sept 11th after 15º no secretion. —
I damped it & placed it Sept 11th (7º 45') at distal end of leaf under damp-Bell-glass
Sept 12th 7º A.m. The damp gelatine has caused no secretion & no closing of leaf.— Whereas the damped meat has caused secretion, judging by narrow strip of Litmus paper & has caused thus one end of leaf almost to shut & it shut suddenly whilst inserting Litmus paper. We thus have that damp food causes secretion & an immeasurably slow movement, ie. if piece large enough.— Perhaps formerly I had not watch ↘
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Evidence very good in both cases, as leaf closed at one end alone very slowly —
(Oct 4th examined the roots of a moderately good plant still growing & there were only 2 single roots about 1 inch in length, proceedingfrom small bulb-like enlargement at the bases of the leaves,
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the insects &c &c long enough so that I did not discover these slow movement. Observe opening of leaf as it will show difference of gelatinefrom albumen & meat
Meat & gelatine of about same size.
Sept. 23d at 7º A.m. Leaf closed at 12º the end with gelatine quite open — the end with meat still half-closed — so no great difference in period of opening — much softened gelatine left. —
Oct 4th Put leaf in water 59º did not close, though kept in for about a 1', but when slowly withdrawn still attached to plant shut rather quickly. (After rain, though doubt on sugar & water)
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Sept 23d 8º Am Dipped leaf into water at 65º did not close — cut it off 1/3from top of petiole, dipped it, did not close— yet when I touched filament closed, put it to stand in water.
Sept 24th standing with stalk in water partly opened—
Sept 25th 7º 40' more open submerged it in water at 62º 1/2 did not close; touched filament & it closed — then completely submerged it, by head & footstalk
A second poor leaf, dipped it whilst attached to plant, did not close— touched it filament & it closed. —
After immersed in water or a mere touch; for the in these latter cases the lobes generally began to reexpand in under a day. On the other hand of
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 1 November, 2022