Did not see description of 'Herniaria glabra' in "English Botany" otherwise would not have sent his paper on it to the Linnean Society, has asked [Thomas] Woodward to procure it for his opinion. Advances in his microscopic investigation into the fructification of 'Fucus': believes it possible to construct a generic character incorporating most of 'Fucus' that will be analogous to Linnaeus' sexual system, except for the "vapour", which is substituted for pollen. Explains his method, wishes others could make similar investigations in different locations and describes [Thomas] Velley's contributions. Observations on '[Fucus] bifurcatus'. Relationship of his book ["Nereis Britannica"] with reviewers and the public, [William] Withering has recommended it to [Carl Peter] Thunberg. Asks if Smith has any specimens of or information on 'Fucus natans' as it was described in "Tour of the Continent", does not believe Linnaeus' claim that it is the "most common vegetable in the world". Would like to compare 'Fucus selaginoides' with 'Fucus tamariscifolius'.