Thanks AB for his paper on the Norwegian flora ["Forsög til en Theori om Invandringen af Norges Flora", Nyt Mag. Naturvidensk. 21 (1876): 279–362]. Appears to CD to be the most important contribution towards understanding the present distribution of plants since Edward Forbes’s essay on the effects of the glacial period ["On the connexion between the distribution of existing fauna and flora of the British Isles and the geological changes which have affected their area", Mem. Geol. Surv. Engl. & Wales 1 (1846): 336–432].

Thanks AB for his letter, his essay on climates ["Theorie der wechselnden kontinentalen und insularen Klimate", Bot. Jahrb. 2 (1882): 1–50, 177–84], and for his photograph. Sends his own.