We may now glance at the glacial succession which has been established for central France. More than twenty years ago Dr. Julien brought forward evidence to show that the region of the Puy de Dôme had witnessed two glacial epochs.[CO] During the first of these epochs a large glacier flowed from Mont Dore. After its retreat a prolonged interglacial epoch followed, during which the old morainic deposits and the rocks they rest upon were much eroded. In the valleys and hollows thus excavated freshwater beds occur which have yielded relics of an abundant flora, together with the remains of _Elephas meridionalis_, _Rhinoceros leptorhinus_, etc. After the deposition of these freshwater alluvia, glaciers again descended the valleys and covered the interglacial beds with their moraines. Similar results have been obtained by M. Rames from a study of the glacial phenomenon of Cantal, which he shows belong to two separate epochs.[CP] The interval between the formation of the two series of glacial accumulations must have been prolonged, for the valleys during that interval were in some places eroded to a depth of 900 feet. M. Rames further recognises that the second glacial epoch was distinguished by two advances of valley-glaciers, separated by a marked episode of fusion. Dr. Julien has likewise noted the evidence for two episodes of fusion during the first extension of the glaciers of the Puy de Dôme. [CO] _Des Phénomènes glaciaires dans le Plateau central de la France_, &c.; Paris, 1869. [CP] Bull. _Soc. géol. de France_, 1884; see also M. Boule, _Bull. de la Soc. philomath. de Paris_, 8^e sér. i., p. 87. Two glacial epochs have similarly been admitted for the Pyrenees;[CQ] but Dr. Penck some years ago brought forward evidence to show that these mountains, like the Alps, have experienced three separate and distinct periods of glaciation.[CR] [CQ] Garrigou: _Bull. Soc. géol. de France_, 2^e sér. xxiv., p. 577. Jeanbernat: _Bull. de Soc. d'Hist. nat. de Toulouse_, iv., pp. 114, 138. Piette: _Bull. Soc. géol. de France_, 3^e sér. ii., pp. 503, 507. [CR] _Mitteilungen d. Vereins f. Erdkunde zu Leipzig_, 1883. We may now return to Scotland, and consider briefly the changes that followed upon the disappearance of the local ice-sheets and large valley-glaciers of our mountain-regions. The evidence is fortunately clear and complete. In the valley of the Tay, for example, at and below Perth, we encounter the following succession of deposits:-- 6. Recent alluvia. 5. Carse-deposits, 45 feet above sea-level. 4. Peat and forest bed. 3. Old alluvia. 2. Clays, etc., of 100-feet beach. 1. Boulder-clay.