Vice-President'' s Address. 107 



short, we should simply liave, as before, an alternation of 

 warm and somewhat cooler climates, but nothing approaching 

 to the glacial and interglacial epoclis of the I'leistocene. 



These conclusions seem to me to be strongly supported 

 by the evidence of ice-action during Tertiary times. The 

 gigantic erratics of ihe Alpine Eocene do not appear to have 

 been derived from the Alps, but rather from the Archiean 

 area of Southern Bohemia. The strata in which they occur 

 are, for the most part, unfossiliferous ; they contain only 

 fucoidal remains, and are presumably marine. How is it 

 possible to account for the appearance of these erratics in 

 marine deposits in central Europe at a time when, as 

 evidenced by the Eocene flora and fauna, the climate was 

 warm ? Are we to infer the former existence of an extremely 

 lofty range of Bohemian Alps which has since vanished ? 

 Is it not more probable that here, too, we have evidence 

 of a lowering of the snow-line, induced by cosmical causes, 

 which brought about the appearance of snow-fields and 

 glaciers in a mountain-tract of much less elevation than 

 would have been required in the absence of high eccentricity 

 of the orbit ? If it be objected that such cosmical causes 

 must have had some effect upon the distribution of life, 

 I reply that very probably they had, although not to any 

 extreme extent. The researches of Mr Starkie Gardner 

 have shown that the flora of the Enolish Eocene affords 



O 



distinct evidence of climatic chanoes. But as the oeo- 

 graphical conditions of that period precluded the possibility 

 of extensive glaciation, and could only, at the most, have 

 induced local glaciers to appear in elevated mountain-regions, 

 it seems idle to cite the non-occurrence of erratics and 

 morainic accumulations in the Eocene of England and Erance 

 as an argument against the application of Croll's theory 

 to the case of the erratics of the Elysch. I repeat, then, 

 that under the geographical conditions of the Eocene, all 

 the more obvious effects likely to have resulted from the 

 passage of a period of high eccentricity would be the 

 appearance of a few local glaciers, the existence of which 

 could have had no more influence on the climate of adjacent 

 lowdands than is notal)le in similar circumstances in our 



