5i 4 SCIENCE PROGRESS 



•of the great sabre-toothed lion, Machairodus, making its stealthy- 

 spring, or hanging, with its great overgrown canines, on to the 

 flanks of a strayed elephant. If he waited by the water places 

 he would be able to watch herds of bison, wild horses, and 

 various kinds of deer, the Irish elk among them, as they came to 

 drink. 



A delightfully warm climate might tempt the traveller to 

 make his bed in the open, but, in any case, he would do well to 

 beware before accepting the shelter of a cavern, for there he 

 might encounter the terrible cave-bear, larger than any existing 

 species, or an animal even still more terrible, no other than man 

 himself. 



Unfortunately we have no time-machine by which we might 

 revisit these scenes ; we must content ourselves by laboriously 

 piecing together the evidence, still more laboriously obtained, 

 which lies sparsely scattered in the gravel of river terraces or in 

 the debris of ancient caves, which is fragmentary at the best and 

 •consequently too often full of apparent contradictions. He who 

 .attempts to construct a consistent story will sometimes wonder 

 whether he may not be weaving a rope of sand. Classifications 

 are made only to be unmade, and as finer and finer subdivisions 

 are proposed, so our difficulties seem only to increase. Among 

 much that is confused, certain facts, however, seem to stand 

 forth in broad outline, and it is to these that we will direct our 

 attention. 



The palaeolithic series may be provisionally divided into 



an upper and a lower group. This proceeding will at all 



•events provide us with useful general terms. These groups 



may be further subdivided into stages as follows : 



rAzilian stage 



Upper Palaeolithic \ Magdalenian stage 



ISolutrian „ 



/Mousterian ,, 



T _, . .... Acheulean „ 



Lower Palaeolithic Chdlean 



IStrepyian ,, 



Some anthropologists, amongst them M. Marcellin Boule 

 and M. Rutot, draw the line between the upper and lower 

 palaeolithic below the Mousterian, and they further subdivide 

 the Acheulean into two sub-stages, which M. Rutot names 

 Acheulean I. and Acheulean II. On the other hand, there are 



