# To P. H. Gosse   7 April [1864]1

Down. | Bromley. | Kent. S.E.

Ap 7.

My dear Sir

If you place large sized pollen on the stigma of any plant & 12° or 18 hours afterwards place the pistil under rather a strong power of a simple microscope & with 2 needles gently tear up the stigma you will easily see the tubes.2 If the pollen be minute it is almost necessary to dissect under $\frac{1}{10}$ inch focal distance; but by gently & blindly teazing the stigma & then transferring the object to the comp. micro: you can generally see the tubes.3 If you once get to know their appearance with any pollen as with geranium, you will never mistake them in any other plant.

I have been almost confined to my bed room for 6 months & therefore cannot aid you about the exchange of Orchids but I fear you will find it difficult to exchange Catasetums,4 for I lately applied to Messrs Veitch5 for species & they informed me that they were so little valued that there were none in the market.

I believe some bi-generic crosses have been made but as the seeds do not germinate, it is impossible to know that the seeds are really well developed

I wish I cd write at more length, Believe me | Sincerely yours | Ch. Darwin

## Footnotes

The year is established by the relationship between this letter and the letter from P. H. Gosse, 5 April 1864.
Gosse had asked CD how to identify pollen-tubes in orchids (see letter from P. H. Gosse, 5 April 1864).
For CD’s use of microscopes, see Correspondence vol. 11, letter to Isaac Anderson-Henry, 2 May [1863], n. 9.
See letter from P. H. Gosse, 5 April 1864 and n. 6.
James Veitch (1815–69), until 1863 in partnership with his father, James Veitch (1792–1863), was the proprietor of a nursery on the King’s Road, Chelsea, and at Coombe Wood, Kingston Hill (Post Office London directory 1864, R. Desmond 1994).

## Summary

Discusses microscopic observation of pollen tubes.

Unable to exchange orchids because of his illness.

## Letter details

Letter no.
DCP-LETT-4454
From
Charles Robert Darwin
To
Philip Henry Gosse
Sent from
Down
Source of text
American Philosophical Society (Carroll 298: Charles Darwin papers B/D25.44)
Physical description
4pp