# From W. E. Darwin   [24 April 1877?]1

Basset, | Southampton.

Tuesday

My dear Father

I am sorry to say I have no dried Rhamnus cath.cus. at all.

I find I marked 11 shrubs in June 1867, and I think I remember going to the Isle of W. afterwards to see about the fruit and finding I was too late to judge.2 I am sure I did

I also find mem: to measure size of anthers & length of stamens, & that when I went over in June 1867 the flowers were too withered.3

I do not suppose these notes are any good.

“In the buds the petals of each kind (i.e. short & long pistilled males) about the same size, in one bud of short pistilled the anthers were larger than in any of the long pistilled, this is probably always the case”

“Short styled wither soonest?” the only distinguishing marks to the naked eye (between the short & long pistilled males) are smaller flowers (slightly) and decidedly shorter pedicals in the shortpistilled, also the stamens & petals rather shorter, especially the stamens”4

“Certainly so says my Father. The stamens are more aborted in the females than the pistils in the males”5

I find I have 2 sketches of long pistilled females & short pistilled females, and written underneath “stamens entirely abortive in each” “The short pistilled (female) ripest the soonest, larger ovary and ovules, disc more cup shaped than in long-pistilled.”6

Rhamnus lanceolata

petal two lobed, embracing anther, (in one longpistilled & one shortpistilled)   the petals of S-pistilled were largest, the length of filament when the anther had been pulled off came up just to the bifurcation of petal, while in long pistilled it fell some little way short of it also in this pair of flowers the anthers were a good dead smaller in the shortpistilled—

[DIAG HERE]

in long pistilled top of stigma reaches nearly up to base of stamen— but in another long pistilled the filaments reached up almost above the bifurcation of petal.7

I enclose diagram & measurements shewing pollen grains in L-pistilled Rh. Lanceolata to be the largest8   Rhamnus flowers soon so I could easily run over in May & measure stamens.

My impression is that there is little difference in the stamens of the two female forms.,

Your affect son | W. E. Darwin

P.S. As far as can be seen & measured from my sketches the much greater depth of calyx tube in the long styled male in Rh. cath. (and it is also much deeper in lanceolata) just makes two pairs of equal heights from base of ovary to top of stigmas or stamens—viz

 height of longstyled males = height of long pistilled female " of short styled male = " of sh. p-d female

“in long styled Male of Cath. & (of lanceolata?) the ridges of the stamens in some cases are carried down inside of disc and form a wheel looking appendage to ovary sometimes attached to it & sometimes not”,— this was not the case in the short styled males as far as my notes9

## [Enclosure 1]

[DIAG HERE]

diameters of Short & Long pistilled are placed on two lines, leaving out z as it is nearly twice the size is probably an error

on measuring it is seen that 15 of S— pistilled equal 14 of L— pistilled therefore L— pistilled pollen grains the largest.

[DIAG HERE]

## [Enclosure 3]

therefore 10 short p— diameters = L— p—d diamet

∴ L— pistilled pollen are largest

[DIAG HERE]

## CD annotations

1.1 I am … judge. 2.2] crossed pencil
6.1 “Short … stamens” 6.4 scored red crayon
7.1 “Certainly … males” 7.2] scored red crayon
10.1 (in … shortpistilled 10.2] ‘∴ ♂’ink
Enclosure 1:
Verso:
 ‘Long Short 1$\frac{1}{3}$ 1 + × 1 1 - × 1 + × 1 - × 1 + × 1 1 + × 1 1 - × 1 - × 1 + × 1 1 + × 1 + × 1 1 + × 1 + × 1 + × 1 1’
pencil

## Footnotes

The date is conjectured from the address, from the reference to planning to observe Rhamnus in May, and from the period when CD was writing Forms of flowers, that is, between November 1876 and June 1877 (see ‘Journal’ (Appendix II) and Correspondence vol. 24, Appendix II). William moved to Basset by 1870 (Correspondence vol. 18, letter to W. D. Fox, 18 February [1870]). In 1877, the last Tuesday in April was 24 April. See also n. 2, below.
William had made observations on heterostyly in Rhamnus catharticus (a synonym of R. cathartica, common buckthorn) in 1866 on the Isle of Wight (see Correspondence vol. 14). The notes in his botanical notebook (DAR 186: 43.61–5) are undated but were probably made in May and June 1866. His notes on R. frangula (a synonym of Frangula alnus, alder buckthorn), dated 8 and 9 August 1866, are in DAR 186: 43.67, and his notes on R. lanceolata (lanceleaf buckthorn) are in DAR 186: 43.68–9; one note, dated 28 August 1866, refers to flower specimens obtained from Asa Gray.
This memorandum is at the end of William’s notes on Rhamnus catharticus and also includes a reminder to himself to ‘examine stigmas of each for papilea [sic]’ and ‘ridges of middle pistilled [stamens]’ (DAR 186: 43.65v). Stigma papillae are minute projections on the surface of the stigma; usually, these are larger in long-styled flowers (see Forms of flowers, pp. 253–4).
These passages are from notes in DAR 186: 43.63v.
The passage is from notes in DAR 186: 43.64r.
These passages are from notes in DAR 186: 43.65v. In his notebook, William actually wrote ‘stamens entirely imperfect in each’.
The passages on Rhamnus lanceolata and the diagram are copied from notes in DAR 186: 43.68v.
The three diagrams are on separate sheets of paper; William sometimes added loose sheets to his notebook; similar sheets are in DAR 186: 43.
The passage is from notes in DAR 186: 43.64v; DAR 186: 43.64v includes a sketch of the wheel-shaped appendage.

## Bibliography

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 27 vols to date. Cambridge: Cambridge University Press. 1985–.

Forms of flowers: The different forms of flowers on plants of the same species. By Charles Darwin. London: John Murray. 1877.

## Summary

Sends notes made in June 1867, on Rhamnus catharticus and R. lanceolatus. Encloses diagrams and measurements relating to pollen size in R. lanceolatus.

## Letter details

Letter no.
DCP-LETT-10343
From
William Erasmus Darwin
To
Charles Robert Darwin
Sent from
Bassett
Source of text
DAR 109: A44, A71–6
Physical description
4pp †, encl 4pp †