JDH cites W. H. Harvey’s observations on Fucus and David Don’s on Juncus as examples of variations that are independent of climate. There are many such cases. Gives his working scheme for categorising variation.

Embryology of plants of low systematic order. Comparative development begins only with first post-cotyledonary leaves.

Curt letter to JDH from George Henslow.

News of Mrs Henslow’s death.

Studying Impatiens, which bears on CD’s problems. Though genus is endemic to India, with over 100 species, CD will be glad to know they do not run into one another.

Finds CD’s results [of his survey of well-marked varieties from A. P. and Alphonse de Candolle’s Prodromus systematis naturalis regni vegetabilis (1824–73)] "very curious and suggestive". Thinks the Labiatae will present an obstacle to him as it is a very large and distinct order with well-defined species and genera. Would like to see him tackle more volumes of Candolle’s Prodromus, as his case can only be established by evidence from mundane plants. CD should beware of generalising from local species variability. A comparison of C. C. Babington’s and G. Bentham’s [British] Floras [Babington Manual of British botany (1843, 4th ed., 1856); Bentham Handbook of British flora (1858)] would be invaluable. Suggests CD write to Ferdinand Müller and Charles Moore in Australia. Moisture favouring extension of species is important for CD’s view.

Sending more Candolle volumes for survey of species with well-marked varieties.

Has begun his introduction [to Flora Tasmaniae]; will not make generalisations.

J. D. Dana’s pamphlet too metaphysical for JDH.