372 BEER, MIOCENE FLOBA OF GREENLAND.^ 



Sequoia sempervirens. Lamb (Red-wood), is its present represen- 

 tative, and resembles it so closely that we may consider S. semper- 

 virens to be the direct descendant of S. Langsdorffii. This tree 

 is cultivated in most of the botanical gardens of Europe, and its 

 extreme northern limit may be placed at lat. 53° N. For its 

 existence it requires a summer temperature of 60° F. Its fruit 

 requires a temperature of 65° F. for ripening. The winter 

 temperature must not fall below 31° F., and that of the whole year 

 must be at least 50° F. Accordingly we may consider the iso- 

 thermal of 50° as its northern limit. This we may then take as 

 the northern temperature of the Sequoia Langsdorjffii, and 50° F. as 

 the absolute minimum of temperature under which the vegetation 

 of Atanekerdluk could have existed there. 



The present annual temperature of the locality is about 20° F. 

 Dove gives the normal temperature of the latitude (70° N.) at \Q'' 

 F. Thus Greenland has too high a temperature ; but if we come 

 further to the eastward we meet with a temperature of 33° F. at 

 Altenfiord. Even this extreme variation from the normal conditions 

 of climate is 17° F. lower than that which we are obliged to assume 

 as having prevailed during the Miocene period. 



The author states that the results obtained confirm his conclu- 

 sions as to the climate of Central Europe at the same epoch (conf. 

 Heer, Recherches sur leClimat et la Vegetation duPays Tertiaire, 

 p. 193), and shows at some length how entirely insufficient the 

 views of Sartorius von Waltershausen are to explain the facts of 

 the case. 



Herr Sartorius would account for the former high temperature 

 of certain localities by supposing the existence of an insular 

 climate in each case. Such suppositions would be quite inade- 

 quate to account for such extreme differences of climate as the 

 evidence now under consideration proves to have existed. 



I^rofessor Heer concludes his paper as follows : — 



I think these facts are convincing, and the more so as they are 

 not insulated, but confirm.ed by the evidence derivable from the 

 Miocene Flora of Iceland, Spitzbergen, and Northern America. 

 These conclusions, too, are only links in the grand chain of evi- 

 dence obtained from the examination of the Miocene Flora of the 

 whole of Europe. They prove to us that we could not, by any 

 re- arrangement of the relative positions of land and water, produce 

 for the northern hemisphere a climate which would explain the 

 phenomena in a satisfactory manner. We must only admit that 

 we are face to face with a problem w^hose solution in all proba- 

 bility must be attempted and, we doubt not, completed by the 

 astronomer. 



Appendix by Editor. 



Memoirs and Reports on the Fossil Plants of 

 Greenland, &c. 



1867. — On the Miocene Flora of North Greenland. By 

 Professor Oswald Heer. Translated by R. H. Scott. Brit. 

 Assoc. Report for 1866, Trans. Sections, p. 53. 1867. 



