Praises unbroken series of CD’s and Francis [Darwin]’s botanical works.

Confirms FD’s Dipsacus observations. Problem of interpreting microscopic filaments as protoplasm or as inorganic and osmotic artifacts.

Accepts CD’s offer to publish his letter, confirming Francis Darwin’s observations [see Collected papers 2: 205–7].

H. Hoffmann’s observations on Amanita contractile filaments must be repeated.

Microscopic examination of secretory gland filaments in Dipsacus leafcups. FD’s pseudopod theory of Dipsacus.

Sends details of H. H. R. Koch’s work on bacteria, including first photographs.

J. S. Burdon Sanderson’s and Koch’s collaboration on systemic fever.

Thinks movement of Francis Darwin’s Dipsacus filaments is an artifact.