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Darwin Correspondence Project

From Daniel Oliver   14 April 1863

Royal Gardens Kew


My dear Sir

Let me beg you never to apologize. I feel so utterly unable to help you in any way unless it be about these little questions.1

The ovule of Primula is amphitropal, or what Agardh wd. call apotropo-amphitropal I suppose.2

Here it is.


a. foramen or micropyle

b. Nucleus (Embr. sac.)

c. Chalaza

d. hilum

It is all but anatropal   If the funicle were adnate quite down to the micropyle then it wd. be so.3

Hofmeister says Primulaceae differ from the great majority of micropetalous plants in having 2 coats to their ovules.4 They have generally but 1 coat.

The inner is thick, the outer very thin. He says the exostome (opening through the outer coat) “liegt vom Endostom (openg. thro’ inner coat) eine Strecke nach der Raphe hin entfernt; der Pollenschlauch hat von jenem zu diesem ein Stück zwischen beiden Eihüllen hinzukriechen”—5 This is a very curious observation. The openings appear thus not to coincide.


What you say is very curious about pollen-tubes penetrating ovules.6 I do not remember any case of direct action except of course the normal place in Gymnosperms.

A good part of a notice of Welwitschia in N.H.R. I gave to the question of this Gymnospermy.—7 I have made drawings from the very interesting Primulas you kindly sent,8—but they do not (seem to me to) furnish decisive evidence against Caspary.9 I am not sure as to direction taken by the tubes but from what I see in an ovary now before me of Primrose think they do not go the round-about way down the sides of the cavity—& up the placenta, but that they strike right upon the top of it near the side of the spear-process from its centre. It must surely be so.


We expect Dr. Hooker anytime.— Today I daresay.—10 The opening at the Chalazal end is something astounding!—11

Ever very sincerely yours | D Oliver

I have re-opened this to say Dr. Hooker is not coming until Friday. Lady H. told me a few days ago his tour had been quite successful so far.12 I have looked further at ovary of Primrose & the tubes land right upon the placenta & do not trouble to go down & up again—at least I dont see them do so,—tho’ they must creep down by each ovule to get to its micropyle—13

Yrs | D O


In his letter to Oliver of [12 April 1863], CD asked about the position of the ovule in Primula; he wondered if it was ‘amphitropal’ or ‘anatropal’. Jacob Georg Agardh was professor of botany at the University of Lund, Sweden (SBL). The use of the term ‘apotropo-amphitropal’ is not apparent in Agardh 1858, but see p. 331 and Tab. XXVII, fig. 1.
The reference is to Wilhelm Hofmeister and Hofmeister 1858, p. 199. Micropetalous: ‘having very small petals’ (OED).
Hofmeister wrote that the exostome, the opening through the outer ovule coat, was ‘situated a distance from the endostome in the direction of the raphe; the pollen tube has to creep between both ovular membranes from the former to the latter’ (Hofmeister 1858, p. 119). The endostome was the opening in the inner ovule coat.
CD had noted that pollen-tubes appeared to penetrate the ovule at the chalaza (see letter to Daniel Oliver, [12 April 1863]). See also letter to John Scott, 12 April [1863].
[Oliver] 1863c, pp. 205–9, was a review of J. D. Hooker 1863a, and appeared in the April number of the Natural History Review.
See letter to Daniel Oliver, 28 March [1863]; CD and Oliver were interested in the morphology of the ovary and its placenta (see also letter to Daniel Oliver, 24–5 March [1863], and letter from Daniel Oliver [26 March [1863]).
Oliver refers to Caspary 1861 and Robert Caspary’s notion of the relationship between the pistil and carpels (see letter from Daniel Oliver, [26 March 1863] and n. 3).
In his letter to Oliver of [12 April 1863], CD asked when Joseph Dalton Hooker would be returning from the Channel Islands (see n. 12, below); Oliver assisted Hooker in the herbarium at the Royal Botanic Gardens, Kew, where Hooker was the assistant director (R. Desmond 1994).
Oliver refers to CD’s letter of [12 April 1863] in which he noted his observation of pollen-tubes penetrating the chalazal end of the ovule.
Oliver refers to Hooker’s mother, Maria Hooker. Hooker was on a trip to Dorset and the Channel Islands of Jersey and Guernsey (see letter from J. D. Hooker, 20 April 1863).
See nn. 6 and 8, above.


The ovule of Primula is amphitropous or what J. Georg Agardh calls apotropo-amphitropous [see Theoria systematis plantarum (1858), tab. 24, fig. 5–6].

Letter details

Letter no.
Daniel Oliver
Charles Robert Darwin
Sent from
Source of text
DAR 173: 21
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 4093,” accessed on 24 June 2017,

Also published in The Correspondence of Charles Darwin, vol. 11