Commends ARW’s papers on parrots

and on the theory of geographical distribution [see 4750].

Wild pigs in Aru Islands must have been introduced and later ran wild. Does ARW have an opinion on the subject?

Orders that one of CD’s Porto Santo rabbits be killed and sent to him.

Asks whether ADB has got young from mating these with females of other breeds.

Encloses two certificates and hopes that he will give the candidates his support. Has just received a letter from Angelo Secchi on the Herschelian prism.

Thanks for kind letter. Pamphlets should have reached him by now. Discourses on the effects of cold and heat on the spinal cord.

Origin of siliceous minerals sent by JH. Planning tenth edition of Principles of Geology. Convinced that changes in position of land and sea were principal causes of climate changes. Questions [James] Croll's theory of astronomical influences on climate, based on data from U. J. J. Le Verrier. Compares earth-pillars in Rhone valley with those in Tyrol. Wants tenth edition to include woodcut of JH's [1821?] drawings of earth-pillars.

Returns the certificates duly signed and also Angelo Secchi's letter, which he was pleased to see. Elaborates on the possible causes of James Nasmyth's 'willow leaves.'

Sends papers with comments. Convinced that the Aru pig is a species peculiar to New Guinea fauna, not a domestic animal that ran wild.

Admires CD’s paper ["Three forms of Lythrum", Collected papers 2: 106–31].