[8] For the most recent discussion of this peculiar case the reader is referred to Professor Castle's paper in _Science_, December 16, 1910. [9] _Paradisus Terrestris_, London, 1629, p. 261. * * * * * Transcriber's note: Corrections made to printed original. Page 36, "two sorts, RP and Rp": 'PR and Rp' in original. Page 51, "9 contain both C and G": 'c and G' in original. Page 184, "in the simplest cases": 'simples' in original. Footnote 3, "turned out to be a masked Dutch": 'turned to out be' in original.