CHAPTER III
Croll. _Phil. Mag._ May, 1868. —— _Climate and Time._ 1875. De Geer. _Geol. Fören i Stockholm Föhr Band 32._ 1910. Gilbert. _Journ. of Geol._, Vol. III, p. 121. 1895. Lowell. _Evolution of Worlds_, p. 197. 1910. Sederholm. _Bull. Comm. Géol. de Finlande_, No. 30, pp. 7-15. 1911. Sollas. _Ancient Hunters._ 1911.