AGE OP HUMAN RACE — RICHARZ 463 



gist, who estimatetl the duration of the entire Ice Age as 17,000 

 years and who ascribed to mankind an age of ;50,000 years. There 

 are still a few such nionoglacialists left, but their number is fast 

 dwindling away. Indeed, it is very difficult to invalidate the 

 weighty evidence for repeated advances and recessions of the ice 

 fcheets. A warm climate, as is known from deposits lying between 

 those of two glaciations, is certaiidy not reconcilable with big ice 

 masses at no great distance. If, for instance, in what are evidently 

 interglacial beds near Toronto, Canada, remains are found of such 

 plants as grow at j)rescnt in southern Pennsylvania, or if close to 

 Hudson Bay in simihir deposits tree trunks occur of 18 inches thick- 

 ness, the climate must have been at that time even milder than to-day 

 and the country must have been free of ice far to the north. 



However, it is still disputed how many times such changes took 

 place. The number of glaciations usually is given as three in north- 

 ern Europe and as four in the Alps. The overwhelming majority 

 of geologists agree that the assumption of at least two independent 

 glaciations with a long warmer interval is imperative. Recently an 

 anthropologist of Vienna, J. Bayer, drops the first glaciation in the 

 Alj)s as unproven, and contracts the last and second last glaciation 

 into a single one, only separated by a minor oscillation of the ice 

 front. Thus two large glacial periods remain with one interglacial 

 period of long duration, in which latter man was present.^" Accord- 

 ingly, the duration of the entire Ice Age is considerably diminished, 

 altliough even Bayer speaks of about 200,000 years. On account, 

 however, of tiie strong opposition of experts, this chronology can 

 not be taken as a standard. 



CONCLUSION 



It is evident from what has been said that there are many uncer- 

 tainties which block any attempt to assign a definite figure for the 

 age of mankind. On the other hand, it would be unreasonable and 

 unscientific to reject all figures as uncertain and unreliable. There 

 are facts which are obvious and wliich are accepted unanimously by 

 all geologists, and these facts warrant the conclusion that man was 

 undoubtedly in Europe 30,000 years ago. Of this number of millen- 

 niums the first half is determined by exact methods, as set forth in 

 this paper; the other half is based partly on an estimate of the reces- 

 sion of the ice where this recession can not yet be measured directly, 

 partly on a verj' conservative estimate of the time required for the 

 advance of tlie ice front from northern to central Europe. Future 

 development of these methods as well as new discoveries may raise 

 this minimum figure considerably and may ])lacc' on a more solid 



"J. nayer, Der Mensch Im Els/.eitalter, Wien, 1027. 



