OF WESTERN EUROPE AND THE MEDITERRANEAN COASTS. 
983 
explanations* may satisfy some of the conditions in particular cases, but none of them 
satisfy all, whereas I think it will be found that the submergence hypothesis not 
only meets the requirements of each particular case, but that it also shows them 
all to be concordant, and such as would pertain to one common and general cause. 
Another important conclusion hinges upon this question. I have beforet pointed 
out the bearing that the position of the Rubble-drift should have in limiting our 
estimate of the time elapsed since the close of the Glacial period. In a paper already 
referred to I had shown cause why that time was not to be measured by Dr. Ceoll’s 
reckoning of 80,000 years, as not being supported by the facts of geology. The 
.position and character of the Rubble-drift show that the transition from the 
so-called Post-glacial beds to the recent Alluvial deposits is very abrupt, and that 
there is an absence of sedimentation or of anything indicative of lapse of time 
between those two series. This conclusion is confirmed by the sections of the Belgian 
caves. There, as we have seen {ante, pp. 927, 928), the Quaternary cave deposits are 
separated by only a few feet of Rubble-drift from deposits of the stone or Neolithic 
age. Nowhere are there any intervening sedimentary beds, or any deposits requiring 
length of time for their accumulation—the only subsequent work requiring time being 
comprised in the alluvial accumulation of our great rivers. 
Besides, on Croll’s hypothesis, Man must have remained comparatively stationary 
during a vastly long period. But how does this accord with the facts. Take 
the earliest works of Man with which we are acquainted—the rude implements 
of the Chalk plateau—and note the difference between them and the implements of 
the later Valley gravels. The former consist of rude flints picked up on the surface, 
and given only such an amount of trimming as to bring an angle to a point, or to 
form a cutting edge out of a blunt natural fracture, or else the stones, just as they 
were found, were used as hammers and trimmers. The valley implements, on the 
other hand, comprise flint tools and Implements carefully worked all over and trimmed 
to certain definite patterns, the workmanship, apart from the want of grinding, being- 
in some cases so fine as almost to equal that of the implements of the Stone age. 
The caves of Central France and of Belgium afford still clearer evidence of the 
progress made by early Man in the interval between these two stages. His work in 
the last Quaternary stage exhibits an intelligence higher than that of many modern 
savages. His harpoons and bone implements were skilfully made, and that he 
possessed some artistic taste is shown by the sculptured bones and horns, and by 
the rude, but sufficiently accurate representations, of the contemporary fauna. How 
can we, then, believe that Man, who had showed himself thus progressive early in 
the Quaternary period, could towards its close have remained for say 70,000 years 
without further progress than that shown by Man of the early Stone period. 
* These have been considered seriatim in a former paper, ‘ Quart. Journ. Geol. Soc.,’ vol. 48, 
pp. 325-328. 
