From J. D. Hooker [9 March 1859]1
Kew
Wednesday.
My dear Darwin
I enclose your sentence slightly modified. I suppose you refer to Phænogamic plants chiefly—2 The greatest division are the two into Vegetables fecundating by pollen tube on ovule contents, in (Phænogams) &—the promiscuous always direct contact of naked cells in Cryptogams.
The Cryptogams are classified very much by vegetative organs, as well as by reproduct. The Phaenogams primarily divide into Monocot & Dicot which appear absolutely distinct.
1 Monocot.
a.Vasc. tissue of promiscuous bundles, in single system
b.Cotyledones of one folded leaf, or if more then alternate
c Germination—primordial leaves alternate—
Root sheathed in radicle.
2 Dicot—
a Vasc. tissue of seriated bundles in double system
b.Cotyledon two & opposite or more in whorls or opposite pairs.
c Germination—primordial leaves opposite.
Radicle lengthens & forms a branching descending axis.
Of Monocot. there are no sub-divisions depending on Embryologic characters of any great moment. Most are albuminous: very few Prealb.
Dicots. branch into Angiosperms & Gymnosperms, depending primarily on reproductive process
1.Angiosperms have the coverings of reproductive organs most highly specialized, the organs & processes simple & as in Monocots.
2 Gymnosperms have coverings of reproductive organs simple & incomplete; the organs & processes themselves infinitely more complex & specialized structurally & physiologically than Angiosperm or Monocot.
If you take reproductive organs as test of highness or lowness then Coniferæ are top of V.K.— if you take coverings of these & neglect the organs themselves, you may place them below Monocots.—but in so doing you neglect the vascular system germination & Embryolog. characters which are all as in Dicots, not as in Monocots3
As to my blessed Essay—it will stand weeks in type, so there will be no manner of hurry in reading & returning proofs.! I am sending it to press—now4
Ever yrs | J D Hooker
CD annotations
Footnotes
Bibliography
Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.
Origin: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. By Charles Darwin. London: John Murray. 1859.
Summary
Outlines the basic categories of phanerogams.
Places Gymnospermae in the dicotyledons.
Evaluates the variable utility of embryological characters in plant classification.
Letter details
- Letter no.
- DCP-LETT-2428
- From
- Joseph Dalton Hooker
- To
- Charles Robert Darwin
- Sent from
- Kew
- Source of text
- DAR 100: 152–3
- Physical description
- ALS 4pp †
Please cite as
Darwin Correspondence Project, “Letter no. 2428,” accessed on 26 September 2022, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-2428.xml
Also published in The Correspondence of Charles Darwin, vol. 7