[3] Skertchley's scheme is now ignored, if not abandoned, by the best authorities. It has been introduced here on account of its historical interest only. Its correlation with the other schemes is speculative.
[4] The differences between the rival schemes of Boule, Penck and Hoernes are best realised by comparing the position assigned to the Solutréan industry by each in turn. The löss and its divisions are not indicated in this Table.
The first enquiry to make is that indicated in the introductory paragraphs of this Chapter, viz. what is the general nature of the fauna accompanying Mousterian implements? Investigation of the records shews that this is characteristically of a northern or a temperate, but not a southern type. For the combination commonly regarded as indicative of the southern type (viz. Elephas antiquus, Rhinoceros merckii, and Hippopotamus major) is very doubtfully demonstrable in this association, save in the very remarkable instance of the Grotte du Prince, Mentone, and Boule (1906) makes somewhat laboured efforts to explain this example, which is exceptional in his opinion. On the other hand, that combination does occur in well-recognised inter-glacial deposits, e.g. the Swiss Lignites of Dürnten, etc.
Fig. 25. Chart of the oscillations of the snow-level in Central Europe during the Pleistocene period. (From Penck.)
In the uppermost space. N Neolithic Age. Ma Magdalenian. Sol Solutréan. Günz, Mindel, Riss, Würm, denote the several glacial phases.
This chart is to be read from right to left; on the extreme right the snow-line is first shewn 300 m. above its present level. Then it falls to nearly 1200 m. below the present level, the fall corresponding to the Günzian glaciation. After this it nearly attains its former level, but does not quite reach the line marked + 300. This chart represents the part marked Glacial Epoch in Fig. 24, with which it should be compared.
The Mousterian implements commonly accompany much more definitely northern animal forms, so that a glacial rather than an inter-glacial age is indicated. But there are four such glacial phases from which to choose in Professor Penck's scheme, and in Professor Boule's scheme there are two (for the ‘Pliocene glaciation,’ appearing in the latter, is hardly in question).
It will be seen (by reference to Table B) that Professor Boule assigns typical Mousterian implements to the most recent glacial period (Boule's No. III = Penck's No. IV = Würm), whereas Professor Penck places them in his penultimate grand period (Riss), carrying them down into the succeeding (Riss-Würmian) inter-glacial period.