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Letter 10517

Darwin, C. R. to Darwin, Francis

[29 May 1876]


Discusses FD’s observations on the protrusion of protoplasmic masses by cells of the teasel. Suggests analogy with amoeba. “I would work at this subject if I were you, to the point of death.”



Monday 30th

My dear F.

You cd. make aggregation less intense by using much weaker sol. of C. ofAmmonia; or by putting minute splinters of glass on glands.

If your case of Teazle holds good it is a wonderful discovery. Try whetherpure water or weak infusion of raw meat will bring out the protoplasmic masses.

The closest analogy seems to me that of an independent Amœba orForaminiferous animal &c which feeds by involving at any point of itsgelatinous body particles of organic matter & then rejecting them— A mass ofrotting insects would give such particles.— Perhaps this is yourview. But I do not understand what you mean by a resinous secretion becomingslimy, or about living insects being caught. I would work at thissubject, if I were you, to the point of death.

If an Amœba-like mass comes out of cells and catches deadparticles & digest them it wd. beat all to fits true digestingplants.

I never saw anything come out of quadrifids of Utricularia & I cd. hardlyhave failed to see them, as I was on look out for secretion. It wd be a granddiscovery. Could you chop up or pound scraping from raw meat, orbetter 12 decayed meat & colour the particles first, & then youcd see them in the protoplasmic masses; for surely you could hardlyexpect (unless there is a distinct hole) that they shd. bewithdrawn within cells of glands.— The case is grand—

Are any orifices or orifice visible in cut-off summit of gland? For heavensake report progress of your work.—

I see in last G. Chronicle another man denies that Dionœa profits byabsorption & digestion, which he does not deny. It seems to me a monstrousconclusion— But this subject ought to be investigated  Especially effects on seed-bearing— Teazles good. for this—

Yours affectionly— | C. Darwin

No doubt marginal glands of Drosera answer to glands on serratures of otherleaves. Probably glands wd. be found on apices of spikes of Dionæa inbud-state.

DAR 271.3: 14


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