212 SECTIONAL ADDRESSES. 



they raise problems whicli have so far baffled the ingenuity of students. 

 The best examples are from Arctic regions, and there is also the rich 

 Jurassic Flora described some years ago by Prof. Halle from the edge of 

 the Antarctic region. Prof. Nathorst demonstrated the occurrence on 

 Ellesmere Land a few degrees south of lat. 80°N. of an Upper Devonian 

 Flora in which species of the fern-like fronds of Archaeopteris are abun- 

 dantly represented : it is noteworthy that these fronds — probably the 

 foliage of a Pteridosperm — are in no way inferior in size to those of the 

 same type discovered in Southern Ireland and Southern Russia. Farther 

 south, but still well within the Arctic Circle, the rocks of the desolate and 

 mist-shrouded Bear Island, in latitude 75°N., have yielded an unusually 

 rich flora which is also Upper Devonian : here, too, well-developed fronds 

 and thick stems of various plants bear eloquent testimony to climatic 

 conditions entirely foreign to European Arctic regions at the present time. 

 The Lower Carboniferous Flora of Spitsbergen compares favourably in the 

 dimensions of the Lepidodendra and other trees with floras of the same age 

 in Central Europe. From lat. 80°N. on the North Eastern corner of 

 Greenland, a few fragmentary remains of widely distributed species mark 

 the most northerly outpost of the early Carboniferous floras. Turning to 

 the Rhsetic period, the work of Dr. Hartz, of Copenhagen, and the more 

 recent and more extended labours of Mr. Harris have given us a thrilling 

 picture of an estuary bordered by a luxuriant and varied vegetation, 

 which can best be described as a detached arctic outlier of the well-known 

 Rhsetic forests of Southern Sweden. Farther east the New Siberian 

 Islands (lat. 75°N.) have afforded samples of Triassic and later floras which 

 give no sign of the stunting efiects of Arctic conditions. Many Jurassic 

 plants are recorded from Franz Josef Land, Spitsbergen, and Northern 

 Siberia which include leaves hardly distinguishable from those of the 

 Maidenhair tree {Ginkgo biloba), the only surviving genus of a once prolific 

 and cosmopolitan group ; also twigs and cones of Conifers, some of which 

 appear to be closely allied to the Californian Sequoias ; some recall 

 existing Araucarias and other genera, which long ago deserted their 

 northern home for southern lands. The best known Arctic Cretaceous 

 Flora is that from Western Greenland (lat. 70°N), a flora especially rich iji 

 Ferns near of kin to species of Qleiclienia that are now mainly tropical in 

 range. Among other Greenland plants are species of Ginkgo ; Conifers 

 allied to Sequoia, Cupressus, and other genera ; leaves and fruit difiering 

 but little from those of the living Bread-fruit tree, leaves believed to belong 

 to a Leguminous plant closely allied to existing species of Dalbergia, species 

 of Magnolia, many forms of Plane tree (Platanus), and examples of other 

 South temperate, sub-tropical, and tropical families. 



Relics of Tertiary Floras have been found on Sabine Island off the 

 East Coast of Greenland on lat. 75°N. , in Grinnell Land still farther north, 

 in Spitsbergen, where leaves of Platanus have been found rivalling in the 

 spread of the lamina the foliage of existing species on the Adriatic coast, 

 and at many other localities within the Arctic Circle. The most striking 

 instance from the other end of the world is the Jurassic Flora of Graham 

 Land first recorded by Prof. Nathorst and subsequently described in detail 

 by Prof. Halle. 



It is superfluous to quote more examples. An important point is that 



