CHAPTER VI

Blake. _Geol. Mag._, p. 72. 1903. Croll. _Stellar Evolution_, p. 48. 1889. Geikie. _Rep. Brit. Ass._ 1892. —— _Nature._ August 4th, 1892. —— _Rep. Brit. Ass._, p. 727. 1899. Haughton. _Manual of Geology_, p. 101. 1871. —— _Nature_, p. 266. 1878. Holmes. _Nature._ July 6th, 1911. Joly. _Radioactivity and Geology._ 1909. de Lapparent. _Bull. Soc. Géol. de France_, Vol. XVIII, p. 351. 1890. —— _Géologie_, p. 225, p. 261, and p. 1958. 1906. Lyell. _Principles._ Tenth Edn., Vol. I, p. 301. 1867. McGee. _Science_, Vol. XXI, p. 309. 1893. Phillips. _Life on the Earth_, p. 119. 1860. Reade. _Geol. Mag._, p. 99. 1893. Sederholm. _Naturen, Helsingfors_, Nos. 33 and 34. 1897. Sollas. _Nature._ April 4th, 1895. —— _Rep. Brit. Ass._, p. 711. 1900. —— _The Age of the Earth and other Geological Studies._ 1905. —— _Presidential Address, Quar. Journ. Geol. Soc._, Vol. LXV. 1909. Upham. _Am. Journ. Science_, Vol. XLV, p. 217. 1893. Walcott. _Journ. Geol._, Vol. I, p. 675. 1893. Watts. _Presidential Address, Quar. Journ. Geol. Soc._, Vol. LXVII. 1911. Wallace. _Island Life_, p. 222. 1892. Winchell. _World Life_, Chicago, p. 378. 1883.