My dear Hooker

Infinite thanks for 3 grand plants of Melastomas;² if anything can be safely made out, I have now good opportunity. I saw again today the 2 sets of plants of Heterocentron raised from the two pollens from same flower, & you never could imagine what a marvellous difference in stature.³ Also many thanks for Vanilla:⁴ it is very different indeed from any orchid which I have seen, & has pollen like Cypripedium(!) & very curious stigma. But oh Lord what will become of my book on Variation:⁵ I am involved in a multiplicity of experiments.— I have been amusing myself by looking at the small flowers of Viola. If Oliver has had time to study them,⁶ he will have seen the curious case (as it seems to me) which I have just made clearly out, viz that in these flowers the few pollen-grains are never shed or never leave the anther-cells, but emit long pollen-tubes, which penetrate the stigma. Today I got the anther with the included pollen-grains (now empty) at one end, & a bundle of tubes penetrating the stigmatic tissue at the other end; I got the whole under the microscope without breaking the tubes: I wonder whether the stigma pours some fluid into the anther so as to excite the included grains. It is a rather odd case of correlation that in the double sweet Violet, the little flowers are double; i.e. have a multitude of minute scales representing the petals. What queer little flowers they are.—⁷

Have you had time to read poor dear Henslow’s life:⁸ it has interested me for the man’s sake, & what I did not think possible, has even exalted his character in my estimation. But I much fear that the Public will think it dull. It will, however, be useful to any clergyman trying to follow, longo intervallo, Henslow’s footsteps.—

How bothered with visitors & hard worked you are.⁹

Good Night | Charles Darwin

P.S. Tell Oliver, I think he must by mistake, when I asked him, have opened the ovarium of female Lychnis dioica: anyhow I can find no vestige of ovules—¹⁰ Tell him that my fancied dimorphisms, like that of Primula, of Oxalis acetosella is all a confounded mistake; only great variability in length of pistils.—¹¹

I have just looked again at V. canina—the case odder;¹² only 2 stamens which embrace the stigma have pollen; the 3 other stamens have no anther-cells & no pollen.— These 2 fertile anthers are of different shape from the 3 sterile others; & the scale representing lower lip is larger & differently shaped from the 4 other scales, representing 4 other petals.—

In V. odorata, (single flower) all 5 stamens produce pollen. But I daresay all this is known.—