266 GENERALIZATIONS. 



Europe, but still inhabits the Nile and the rivers of Asia Minor. 

 In the calcareous tufas of Aygalades, near Marseilles, teeth of 

 Elephas antiquus have been found with leaves of the European 

 and Canarian laurels. From the island of Spitzbergen Prof. 

 Heer has met with traces of a similar interglacial period which 

 was a little warmer *. 



The interglacial period was succeeded by a fresh increase of 

 the glaciers, constituting a second Glacial period. It was followed 

 by another elevation of temperature, which, taken as a whole, 

 has continued to the present day, at least so far as we can ascer- 

 tain by reference to human history f. 



* See the < Flora and Fauna of Spitzbergen ' (p. 84), by Prof. Heer. As 

 the phenomena of the Interglacial period have often been confounded with 

 those of the Glacial period, several errors have been committed. 



t It is probable that at the first appearance of Man in Switzerland the 

 climate was considerably colder than at present. This hypothesis is founded 

 upon the area ranged over by the reindeer in Europe at this period, which 

 has been also called the " Reindeer period." In a station of reindeer near 

 Veyrier, at the foot of the Sal eve, there have been found, besides bones, 

 teeth, and fragments of the antlers of the reindeer, the bones of about thirty 

 individuals of Tetrao lagopus, remains of the Alpine hare, the marmot, the 

 chamois, the ibex, the bear, the lynx, &c. At Schussenried, near Ravens- 

 burg, the jaw of an Arctic fox and some mosses of the Arctic zone have been 

 discovered with the reindeer. Advancing to the next stage in the history of 

 Man, we arrive at the lake-dwellings. During the first part of that epoch 

 which has been denominated the Stone age, the climate must have been 

 the same as at the present day. This similarity of climate is demonstrated 

 by well-preserved remains of plants. The lake-dwellers cultivated several 

 kinds of grain, as, for example, barley, various species of wheat, among 

 which are found the Eg} r ptian wheat (Triticum turgiduni), and two kinds of 

 millet (Panicum miliaceum and Setaria italica). Among the weeds Prof. 

 Heer has found the corn-cockle (Ayrostemma githago) and the common cen- 

 taury ( Centaurea cyanus), which doubtless inhabited the cornfields, whilst the 

 Silene cretica grew among the flax. Recently Prof. Heer has found several 

 fruits of the Silene cretica, filled with well-preserved seeds, in bundles of flax- 

 stalks buried in the lake-dwelling of Robenhausen ; it now grows only in 

 Mediterranean countries, where it is frequent in the fields of flax ; and it thus 

 indicates that the inhabitants of the Swiss lacustrine habitations imported 

 their flax-seeds from the soutu of Europe, and that as the flax seed ripened 

 at Robenhausen the climate of that locality was not colder than at the pre- 

 sent day. This fact is confirmed by the spontaneously growing plants, among 

 which Prof. Heer cites the yew (Taxus), hornbeam (Carpinus), holly (Ilex), 

 and the water-chestnut ( Trapa). The Arctic animals, such as the reindeer, 



