86 Capt. F. W. Hutton on the Origin of the 



Possibly therefore the ice would be reduced in quantity. 

 Both Mr. Wallace and Dr. Croll * allow that high eccen- 

 tricity alone would not bring on a glacial epoch unless the 

 geographical conditions were favourable ; and so they would 

 no doubt allow on reconsideration that no severe glacial epoch 

 could occur in the southern hemisphere under the present 

 conditions. In New Zealand more snow might fall in winter, 

 but probably it would be all melted again by the greater heat 

 of summer ; and, as the mean annual temperature would be 

 higher with greater eccentricity, it is not likely that our 

 glaciers would be much larger at that time than now. Under 

 the present geographical conditions greater eccentricity might 

 produce a greater precipitation of moisture in the form of 

 snow or rain in winter and greater floods in summer, and 

 therefore a diluvial epoch, but not a glacial epoch. 



Now there is no reason to suppose that any very important 

 geographical changes occurred in the southern hemisphere 

 during the Pleistocene period ; on the contrary, as will appear 

 presently, the insular floras prove long isolation ; but there 

 are several reasons for thinking that a diluvial epoch has 

 Qccurred in New Zealand at a comparatively late date — that 

 is, during the depression which, as we shall presently see, 

 followed our last great glacier epoch. These reasons I have 

 lately given in a paper sent to the Geological Societyf, and I 

 need not reproduce them here ; but the evidence is not con- 

 fined to New Zealand alone. 



The Pampasan formation of South America, so ably 

 described by Darwin, which contains the remains of an enor- 

 mous number of huge terrestrial mammals, is much like the 

 so-called " loess formation " of Banks peninsula and Oamaru, 

 and in both cases violent and often-recurring floods sweeping 

 down to the sea torrents of mud and the bodies of drowned 

 animals seem necessary to account for the phenomena. Also 

 in a letter to me (dated June 1884) Prof. R. Tate says that 

 strong evidence is afforded by the distribution of Diprotodon 

 that Australia has passed through a pluvial period. So that 

 there is evidence in New Zealand, in Australia, and in South 

 America to show that the last high eccentricity of the earth's 

 orbit may have produced in the southern hemisphere a 

 diluvial epoch ; but we shall see directly that there is no 

 evidence at all of its having produced a glacial epoch J. 



* Phil. Mag., Feb. 1883, p. 81. 

 t " Sketch of the Geology of New Zealand." 



X Fur evidence of a diluvial epoch in South Africa see Stow, Quart. 

 Journ. Cieol. Soc. xxvii. p. 543. 



