EULA AIM, (CALAN CTCAIE, JIVEIAOSH INS, 269 
penetrated. If the epigene agents of. change worked no more 
actively then than they did in later interglacial times or than 
they do in our own day, we should be led to infer that the earlier 
were of much longer duration than the later stages. But I doubt 
whether that inference would be justifiable. Such evidence as 
we have seems to indicate that the climates of the earlier inter- 
glacial stages were warmer and more humid than those of later 
epochs—and this means more active weathering and more 
energetic fluviatile erosion. If we base our estimate of the 
duration of the earlier interglacial epochs upon the present rate 
of erosion and accumulation, then doubtless we shall be led to 
conclude that these earlier stages were more protracted than the 
later. But it would seem more reasonable to take the latest 
interglacial epochs—those, namely, which approached most 
nearly to existing conditions—and endeavor to measure the 
duration of these by reference to the present rate of erosion. If 
we could ascertain approximately the time required for the 
erosion and accumulation which took place during the Lower or 
the Upper Forestian stage we should perhaps have a better index 
to the duration of interglacial epochs generally. In a word, the 
present rate of epigene action cannot be much less than that of 
late interglacial times, but it must have been considerably 
exceeded by that of earlier interglacial stages. 
For ready reference I append a tabular statement of the 
glacial succession in Europe: 
EUROPEAN GLACIAL AND INTERGLACIAL STAGES. 
XI. Upper Turbarian = Sixth Glacial Period. 
X. Upper Forestian = Fifth Interglacial Period. 
IX. Lower Turbarian = Fifth Glacial Epoch. 
VIII. Lower Forestian = Fourth Interglacial Epoch. 
VII. Mecklenburgian = Fourth Glacial Epoch. 
VI. Nendeckian = Third Interglacial Epoch. 
V. Polandian = Third Glacial Epoch. 
IV. Helvetian = Second Interglacial Epoch. 
III. Saxonian = Second Glacial Epoch. 
II. Norfolkian = First Interglacial Epoch. 
I. Scanian = First Glacial Epoch. 
JAMES GEIKIE. 
