Regrets delay in sending pamphlets for JDD.

Thanks him for information concerning cirripedes.

Sends thanks to Charles Pickering for information about plant distribution.

Discusses boring species of cirripedes.

Believes Harry D. S. Goodsir mistaken about parasites on Balanus ["Observations on organs of generation in Crustacea", Edinburgh New Philos. J. 36 (1843–4): 183–6]. In fact parasites are the males of the species.

Admires chimes analogy in JH's 'On Circulating Functions' [1818]. Resumed interest in partitions of numbers in development of periodic functions. Finds JH's method superior. Encourages him to publish it. WH and Augustus De Morgan developed original method, which WH erred in attributing to Leonhard Euler. De Morgan's paper to Cambridge [Philosophical] Society demonstrates theorem leading to proof of Euler's theorem.