Page:Early Man in Britain and His Place in the Tertiary Period.djvu/106

78 for the most part, of deciduous trees, maples, alders, poplars, willows, elms, and ashes, with an under- growth of bog-whortleberries (Vaccinium uliginosum). These are found at a height of 700 mètres above the sea, while that of Meximieux is about 200 mètres. Yet a higher zone is met with at St. Vincent in the Cantal at 1200 mètres above the sea, in a forest buried under lava, which consisted of pines, among which one (Abies pinsapo) grows in Andalusia, in regions between 1100 and 2000 mètres high.

These three zones of forest growth, so ably interpreted by M. de Saporta, were probably to be met with only in central and southern Europe where there were mountains. The evergreen forest did not extend far beyond the latitude of Paris, and the deciduous trees probably formed a belt extending over the low country of Britain and northern Germany, while the sombre forest zone of pines was to be seen still farther north. The cinnamon trees and the sabal palms (see Fig. 8), which in the Meiocene times had extended as far north as the Lower Rhine, in the early Pleiocene age were restricted to the region of Italy.

The climate necessary for the growth of the flora of Meximieux is one considerably hotter, as well as more moist, than that of the neighbourhood of Lyons at the present time. The winters must have been mild and the heat of summer above 20° centigrade to allow the Nerium to flower, the bamboos to flourish, and the fruits of the pomegranate to ripen. The mean annual temperature necessary for these is estimated by M. de Saporta at 17° (62⋅6 Fahr.) centigrade, or about eight degrees more than