RECORD: Darwin, C. R. [1861-]. [Draft of Orchids, pp. 80-82] Chapter II pp. 130, 128. with notes by George Darwin on versos. CUL-DAR51.C12-C13. (John van Wyhe ed., 2002-. The Complete Work of Charles Darwin Online, http://darwin-online.org.uk/)
REVISION HISTORY: Transcribed and edited by John van Wyhe 11.2025. 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.
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The mean distance between the centres of conseq. molecules (called hereafter M.D) } < 1/100,000,000 & > 1/2,000,000,000 of a centimètre
a Centimètre = .393708 of an inch
= 393.708 thousths. of an inch
or = 3937.08 10 thousth. of an inch
∴ MD < 393.708/100,000,000 > 393.708/2,000,000,000 of 1/1000th of an inch
or M.D < 3937.08/100,000,000 > 3937.08/2,000,000,000 of 1/10,000th of an inch
Call the vol. of cube whose corners are the centres of 4 molecules X for shortness
∴ X < (393.708) 3 / (100000000) 3 cubic 1/100th of inch
& > (393.708) (196.85403 / (1000000000) 3 cub. 1/1000th of inch
∴ cubic 1/1000th of inch > (100000000/393.708) 3 X
< (1000000000) 3 / (196.854) 3 X
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130.
Chapter II
their original position in the anther-cells. They then quickly depress themselves till they lie parallel to the bristle; and if the bristle, slightly diverging; and when the bristle, being held in the same relative position, is inserted into the nectary of another flower, the two ends of the pollinia accurately strike the two stigmatic surfaces lying close on each side of the mouth of the nectary. I am, however, not quite sure that I understand the by what the whole mechanism causing the pollinia to divergence for I find that moths often remove one pollinium alone; and this fact leads me to suspect that they insert their probosces obliquely into the nectary.)
from one side of the flower.) (The flowers smell very sweetly and the abundant nectar
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Similarly
Cubic 1/10,000th of inch > (100000000/3937.08)3 X
< (1000000000/1968.54)3 X
Now log 393.708 = 2.5951742 [x] 3 [=] 7.7866226
log 100,000,000 = 8.0000000 [x] 3 [=] 24.0000000 [-] 7.7855226 [=] 16.2144774
log 1638617 =
∴Cubic 1/1000th inch > 16,386,170,000,000,000 X
or 16,386 million million X
Again log 196.854 = 2.2941442 [x] 3 [=] 6.8824326
& log 1,000,000,000 = 9.0000000 [x] e [=] 27.0000000 [-] 6.8824326 [=] 20.1175674
log 1310993 =
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 28 November, 2025