Sends HA’s paper ["On leaf arrangement"] with a supporting note [from CD] to Royal Society.

Has sent phyllotaxy paper to G. G. Stokes with the letter from CD to show credentials.

Will not have time to read new Sachs edition CD offered.

Thanks for CD’s sponsorship of paper [Proc. R. Soc. Lond. 21 (1873): 176–9].

Thanks for congratulations on appearance of abstract of HA’s paper [Nature 7 (1873): 343–4].

Explains again his theory of "contraction with twist" by which compact buds and a spiral phyllotaxy have evolved. Explains how the peculiar phyllotaxy of the teasel is explicable by this process of "condensation".

The Royal Society referees have rejected HA’s phyllotaxy paper, and it will not be printed in Philosophical Transactions. HA is not sorry for he has found new facts which limit the applicability of his views. Now believes that the original leaf arrangement was not necessarily always two-ranked but rather that existing arrangements have developed from a variety of forms with differing numbers of leaf-ranks.

Illustrates, with reference to different species of Gasteria, the role of twisting in the development of leaf arrangement.

W. J. Beal’s paper ["Phyllotaxis of cones", Am. Nat. 7 (1873): 449–53] shows incompleteness of HA’s theory, but does not invalidate his basic principles on origin of leaf arrangement or the broad applicability of the theory.

Has rewritten paper on leaf arrangement after criticism by Royal Society referees. Has found new factor influencing leaf arrangement, i.e., spontaneous variability in the number of vertical leaf-ranks.

Sends article on temporary color-blindness. G. B. Airy's book on sound [On Sound and Atmospheric Vibrations] is finished.

Observations on various forms of [hemianopsia], which afflicts HA, his father [G. B. Airy], and JH. Detailed description of recent attack. Seven sketches with captions.

JH's approval encourages HA to publish account [of hemianopsia]. JH may keep HA's drawings. Notes on attack suffered by JH.

Writing about [hemianopsia] for doctor's thesis at Cambridge. Asks permission to quote report of JH's attack [see JH's 1868-5-4].

Received JH's permission to quote JH [in HA's thesis on hemianopsia] and describe JH's latest attack, including 'patches of coloured checquer work.'

Describes difficulties in producing glass pen and attaching it to pendulum to produce precise curves for aligning equatorial [telescope mount]. Sent artistic sample to JH's wife.