From George Henslow   7 April 1866

10 South Crescent | Bedford Sq | W.C.

April 7th /66

My dear Sir

I send by this post a few copies of the “Science Gossip”, which I happen to have as duplicates, so that you can obtain a knowledge of their General character.1 Also one or two Nos. of the Leisure Hour in which I have written short papers, that may perhaps interest you, as being connected with my fathers doings. Please to accept them. (One has not my name attached viz: “Phosphate Nodules”.)—2

I have already exhibited the Coryanthes—you so kindly gave me—to the delight & astonishment of several: it certainly is a most wonderful contrivance.3

With regard to the remark I made about the relative Nos. expressive of the fertility of Primrose.— I was referring to the Tab. II p. 89. P. veris

By calculation

good pods Weight of seed in grains Long: styled as 100 to 42*

Homoc.) long styled) ‘ 100 ’ 62

Heteroc.) Short styled:) ‘ 100 ’ 30

Homoc.) Short styled) ‘ 100 ’ 44*4

Heteroc.)

Comparing these (*) it seems, they run very close!5 does that proportion mean that the seed from every 100 good pods weighed, on average (by calculation of course) 42 grains?

Again thanking you for a very pleasant visit last Monday,6

Believe me | My dear Sir, | Yours very faithfully | Geo Henslow

C. Darwin Esq.

1
Hardwicke’s Science-Gossip: an Illustrated Medium of Interchange and Gossip for Students and Lovers of Nature was established in 1865. Published monthly, it was advertised as ‘a medium of exchange and Chit-chat … for lighter and more varied information’, complementing the publisher’s other journal, Popular Science Review (back page of issue 2).
2
Henslow’s article ‘Phosphate nodules’ described the introduction of phosphates as a manure for root crops by Henslow’s father, John Stevens Henslow; it was published in Leisure Hour, 11 July 1863, pp. 436–8 ([Henslow] 1863). Henslow also refers to his signed article ‘The wild flowers of Shakespear’, which appeared in Leisure Hour, 9 April 1864, pp. 229–31 (Henslow 1864).
3
CD probably gave Henslow a plant of the orchid genus Coryanthes when Henslow visited Down from 2 April 1866. CD had described Coryanthes in Orchids, pp. 277–8, remarking that drops of the secreted nectar were collected in the hollowed end of the labellum ‘just like a bucket suspended some way beneath a dripping spring of water’. The section on Coryanthes is considerably expanded in the second edition (Orchids 2d ed., pp. 173–6). See also Origin 4th ed., p. 230, ‘Fertilization of orchids’, p. 151 (Collected papers 2: 153–4), and Correspondence vol. 12.
4
The table is an extract from table II in ‘Dimorphic condition in Primula’, p. 89 (Collected papers 2: 56); the four lines show, successively, the results of pollination of long-styled flowers of Primula veris by own pollen and pollen from short-styled flowers, and of pollination of short-styled flowers by own pollen and pollen from long-styled flowers.
5
In ‘Dimorphic condition in Primula’, p. 88 (Collected papers 2: 56), CD calculated that homomorphic unions yielded a weight of 35 grains of seed per 100 ‘good capsules’, while heteromorphic unions yielded 54 grains. Henslow here shows that the difference is narrowed considerably if the second and third rows of results are omitted.
6
See n. 3, above.

Please cite as “DCP-LETT-5048,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-5048