IV] PRESERVATION OF PLANTS 69 



reference may be made to the wealth of material 

 collected within the Arctic circle. The problems 

 suggested by the discovery of plants in rocks of 

 various ages in North Siberia, Spitzbergen, Franz 

 Josef Land, Bear Island, Greenland, and in many 

 other localities in the far north are too difficult 

 and far-reaching to be discussed in these pages. In 

 the Cretaceous and Tertiary strata of the west coast 

 of Greenland and Disco Island from 69° to 72° north 

 latitude, to refer only to one case, a great number 

 of plants have been obtained by several of the earlier 

 Arctic explorers and more recently by members of 

 one of the Peary Expeditions. At the present day 

 on the fringe of land on the western edge of Green- 

 land which is not permanently covered with ice, 

 a considerable number of herbaceous plants are able 

 to exist and to produce seed during their concentrated 

 period of development ; while trees are represented 

 only by a few low-growing shrubs such as the dwarf 

 Juniper. In places accessible to investigation beyond 

 the ice-covered hills of northern Greenland the rocks 

 have been shown to consist of Cretaceous and Tertiary 

 sediments containing fossil plants associated with 

 seams of coal. From these beds numerous Dicotyle- 

 dons have been obtained, some of them almost 

 identical with living species characteristic of sub- 

 tropical or tropical countries. In the lowest of the 

 Cretaceous series no Dicotyledons have been found, 



