Sends CD a paper ["Ant-agency in plant structure", published in Spruce Notes of a botanist on the Amazon and Andes, ed. A. R. Wallace (1908)] on plant structures he believes are the work of insects; asks him to forward it to the Linnean Society [read 15 Apr 1869].

Writes of his support for the Origin, before which he had been much concerned by the delimitation of so-called species.

Is pleased with the interest JH is taking in his volume. Understands the difficulty of comprehending it at once. Further comments on his own dynamical theory of dispersion.

Thanks for answers and for notice on Apteryx [Maerurus ?], which JH remembers watching Richard Owen inspect. Interested in W. B. Carpenter's and C. W. Thomson's ['Bathybius?]' as origin of chalk-flint. Discusses inorganic chemical allotropes. Organic allotropes may exist, serving as 'agents of vital action' and subject to a higher power.

RS’s facts are remarkable. A year or two ago CD would not have believed ants could produce an inherited effect, but he has "lately come to believe rather more in inherited mutilations". However, CD is not satisfied that the sacs are inherited and urges RS to produce any other evidence he might have.