Thanks for sending paper on geological development (Dana 1856). Discusses infertility of species. Discusses first part of Asa Gray’s paper (A. Gray 1856–7). Thanks for note on the Cave Rat. Discusses a new species of fossil cirripede, in the genus Chthamalus. Explains his interest in pigeon breeding.

Thanks for correspondent’s Untersuchungen [? Über das Klima und die Vegetationsverhältnisse des Tertiärlandes (1860)]. CD has always considered subject interesting and important.

Comments on MTM’s article ["On the existence of two forms of peloria", Nat. Hist. Rev. n.s. 3 (1863): 258–62]. Cites interesting case of peloric flower.

Condolence on death of HJ’s daughter; "I know from old experience how bitter a loss it is".

Thanks for information about intelligence of dog.