2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 82 



likewise comfort to meteorologists confronted with the traditional 

 view of a lack of climatic zones during most of the eons of earth 

 history. I propose to pass in review what we know of the past dis- 

 tribution of plants in the Arctic, after which I will endeavor to evaluate 

 what they mean in terms of climate. 



Aside from some very scrappy plant fragments from the Silurian 

 of Norway, the oldest traces of land plants in the north occur in rocks 

 of Devonian age. Devonian plants have been discovered within the 

 Arctic Circle at the three localities shown on the accompanying map. 

 (fig. i). These range from a few scraps, such as those found in 

 Ellesmere Land and Spitzbergen, to the extensive flora found on 

 Bear Island which embraces 31 named forms. These three floras 

 are of upper Devonian age but not necessarily synchronous, since an 

 earlier and a later horizon is represented on Bear Island and probably 

 on Spitzbergen. 



I have shown on the map (fig. i) the occurrence of some other 

 Devonian floras outside the Arctic Circle and some in lower latitudes 

 in order to give an idea of the known geographical range of Devonian 

 plants in the present North Temperate Zone. The oldest of these is 

 the Lower Devonian flora of Roragen, Norway, embracing eight 

 very interesting forms. Of particular interest are the Middle Devonian 

 plants found in silicified peats at Rhynie in northern Scotland and 

 the flora described recently from Germany, since these give us our 

 first considerable insight into the structure of these ancient plants. 



In looking over the list of identifications from Bear Island, all 

 except Pseudobornia are seen to belong to widely distributed types, 

 several are identical with species from the south of Ireland, and similar 

 forms occur rather generally in lower latitudes. There are several 

 seams of coal at both the older and younger horizons, to which 

 Bothrodendron contributed a large amount of material. Beneath the 

 coal seams are underclays with roots in place and the plant remains 

 show no sorting — that is, delicate material is mixed with stems and 

 branches of all sizes — both facts indicating conclusively that the bulk 

 of the material was not transported but grew in the immediate vicinity. 

 The same statement is true of the Devonian of Ellesmere Land. 



The plants of the Devonian are so remote from living forms that 

 I do not feel that any conclusions regarding the climate are warranted 

 beyond the statement that they show that there were no climatic 

 barriers to prevent most of the types found in Latitude 45° to 50° 

 extending northward to Latitude 75°. There are, however, certain 

 types which have not yet been found in the north, such as Eosper- 



