PLEISTOCENE CAVE-DEPOSITS. 101 



lithic deposits comes a mass of yellow clay and angular stones, 

 which is often covered with deposits of loam and brick-earth. 

 Belies and remains of the Neolithic Age occur at and near the 

 surface of these superficial accumulations, but are never met 

 with in an underlying position. The yellow clay, therefore, 

 takes its place in the series between the accumulations belong- 

 ing to the Old Stone Age and those which mark the later or 

 New Stone Period. 



M. Dupont recognises two stages in the Palaeolithic Period, 

 one of which is called the Mammoth period, and the other, 

 which is the more recent, the Eeindeer period. These names 

 are also employed by French geologists to mark similar stages 

 in the floor-deposits of the caves in their country, but they have 

 never met with much acceptance in England. The names 

 indeed are unfortunate, for it is quite certain that the reindeer 

 occupied Belgium and Prance in the so-called Mammoth period, 

 and we have no reason to doubt that the mammoth lived down 

 to the very close of the Palaeolithic Age. It is quite an open 

 question whether it did not even survive in Europe to Neolithic 

 times. But while the mere names may be cavilled at, there can 

 be no doubt that M. Dupont and others have brought forward 

 evidence sufficient to show that the closing stage of the Palaeo- 

 lithic Period was marked by the abundance of the reindeer and 

 other northern forms, and by the presence of the extinct species 

 in greatly reduced numbers. The implements belonging to the 

 so-called Eeindeer period of Belgium are also indicative, upon 

 the whole, of more advanced conditions than obtained during 

 the earlier phases of the Palaeolithic age, as these are repre- 

 sented in the caves of that country. 



The fluviatile deposits which occupy the floors of the Belgian 

 caves have of course been carried into them by the streams, but 

 many of the caves are now far removed beyond the reach of 

 even the highest floods. It is clear then, according to M. 

 Dupont, that such caves bear witness to the gradual erosion or 

 excavation of the valleys, and that river-deposits which occur in 

 caves at the highest levels must be the most ancient of the 



