354 CLIMATIC CONDITIONS OF THE GLACIAL EPOCH. 



the term " Glacial epoch " could be used with propriety to designate the 

 period when the glaciers of a few of the more favorably situated ranges of 

 that continent covered an area at the most not more than a few hundred 

 square miles greater than thnt which they now occupy. Indeed, when we 

 consider what an iuimen^^e diminution thei'e has been in the water surface of 

 Asia during later geological times, we might be inclined to admit that there 

 has not been by any means a corresponding decrease of the glaciers, if we 

 did not call to mind that — as already explained — this changed phase of the 

 physical geography of Asia was in part the result of a lowering of the mean 

 temperature, a circumstance which must necessarily counterbalance, to a 

 certain extent, the influences tending to diminish jjrecipitation. 



The entire Southern Hemisphere, with its comparatively small area of 

 land, may be disposed of in a few words, since we know nothing positively 

 of the extent of jDast as compared Avith present glaciation in the Southern 

 Polar regions. That the amount of snow and ice within the Antarctic Circle 

 is very possibly larger now than ever before has been already stated ; there 

 is nothing farther to be said, in the present connection, in regard to those 

 southern lands and seas. 



That the glaciers of New Zealand have diminished somewhat in size since 

 the time of their greatest extension seems very clearly indicated by the 

 investigations of Haast and others. Other proofs of the decrease of precipi- 

 tation in that region are so marked that it would indeed be remarkable if 

 that afforded by the recession of the ice masses were entirely wanting. 



In regard to either present or past glaciation in Australia we know 

 absolutely nothing. There is no reason to suppose that glaciers ever existed 

 there. Nearly the same may be said of Africa. Mr. Maw thinks that traces 

 of former glaciers occur in the High Atlas, describing what he considers 

 "unquestionable moraines" in the province of Reraya, at an altitude of 

 0,000 feet. Althouo;h admitting; that no scratched blocks or strite were 

 found, he thinks that there can be no doubt of the morainic character of the 

 detrital accumulations in question.* Other observers in that region have 

 not been able to confirm the accuracy of these views. That there should 

 have been a moderate development of ice or permanent snow on the Atlas 

 Range is not impossible ; but, as the evidence now stands, this can hardly be 

 considered as having been proved. 



* Jomii:il of a Tour in Maioc-co anil tin- Great Atlas, Ijy J. I). Hooker and ,1. Ball, with an Appendix includ- 

 ing a sketch of the Geology of Maroeco, by George Maw, London, 1878, p. 461. 



