JDH hopes to send Asa Gray copies of GENERA PLANTARUM with the autumn box of 'distributa'. JDH discusses Sir John William Dawson's criticisms of one of his essays concerning plant distribution [possibly JDH's introductory essay from FLORA ANTARCTICA], addressing each point in detail. Dawson's objections centre on the flora of Scandinavia & supposed geological inaccuracies, many concerning Greenland. In the past JDH & Sir Charles Bunbury have quashed some of Dawson's palaeobotany papers sent to the Geological Society. JDH is convinced his own conclusions are sound, they have the support of James Hector & Sir Charles Lyell. Dawson is against Darwinism & the theory of evolution by natural selection. JDH notes that there is currently a lot of changes in geological theory & hypotheses in the discipline are difficult to prove, there is an argument about the effectiveness of current species variation & distribution in determining past land formations. JDH believes geological & biological evidence must both be taken into account to form a strong hypothesis. He makes the point that all facts began as theory, just as absolute specific creation is now questioned so may creation by variation be disproved, or it could become established fact. JDH mentions his own work on Welwitschia [mirabilis], specifically characteristics of ovules in male & female flowers, & Gray's work on Cypripedium. Thanks Gray for Asimina & urges him to write a systematic resume of American flora.