NORTHERN TEMPERATURE. 143 



country), as well as on the margins of the great bay of Dantzig, 

 numerous fossil plants have been collected in the lignites and in 

 the shales formed of mud and clay *. The palms are entirely 

 wanting ; so far as we know, they did not pass the latitude of 

 51'05 N. in Germany. But in the Bay of Dantzig we still 

 find some fig-trees and laurels, two cinnamons (Cinnamomum 

 Scheuchzeri and C. lanceolatum), besides evergreen oaks and 

 species of Andromeda and Myrica. The swamp- cypresses (Tax- 

 odium distichum) were very abundant, as were also the Sequoia. 

 In Samland a poplar (Populus Zaddachi) and a Rhamnus (R. 

 Gaudini) are associated with the fruits and seeds of a Gardenia. 

 At the present day Dantzig has a mean temperature of 7*6Cent. 

 (or 45 0> 7 Fahr.). If we assume that in these northern regions, 

 as in Switzerland, the temperature of the Lower Miocene was 

 9 Cent, (or 16 0< 2 Fahr.) higher than at the present day, we 

 shall have for these localities a climate of 17 Cent, (or 62'6 

 Fahr.), which would be quite suitable to the above-mentioned 

 Miocene flora. Professor Goppert has discovered at Schossnitz, 

 near Breslau, a rich flora of the CEningian epoch. In it 

 tropical and subtropical forms are naturally wanting ; for if we 

 calculate the temperature of the fifth or highest stage of the 

 Miocene according to the existing 'temperatures, we obtain a 

 climate of 15 Cent, (or 59 Fahr.), which explains the presence 

 in Silesia of the swamp-cypress, of the liquidambars, and of 

 some evergreen oaks; but, on the other hand, excludes the 

 palms, cinnamon-trees, and acacias from that part of Germany, 

 although they adorned the Miocene forests of Switzerland and 

 Northern Italy. 



The hypothesis of a lowering of temperature in the north is 

 confirmed by the Miocene flora recently discovered in the arctic 

 zone f. Thus, in the fossil flora of Spitzbergen, between 78 and 

 79 N. lat., the Swedish naturalists Nordenskjold and Malmgren 

 have discovered more than 100 species of plants. In this num- 



* Prof. Heer has described them in his 'Miocene Flora of the Baltic.' 

 Konigsberg, 1869. 



t Prof. Heer has described these plants in his ' Flora Fossilis Arctica,' 

 vol. i. 1808, vol. ii. 1871, with 108 plates. 



