51�Թ�

The best opinion of today, and it is well-nigh universal, is that the Mosaic record refers to indefinite periods of time corresponding to the great divisions of historical geology.

Historical geology of the Antillean-Caribbean region.

Moreover, although historical geology demands cycles of varied duration and magnitude, it does not furnish evidence of any rigid periodicity causing the cycles to be uniform in length or intensity.Most important of all, a satisfactory explanation of climatic changes and crustal deformation must take account of all the agencies which are now causing similar phenomena.

This is the story of the geological period as known to historical geology.

Attention has therefore been directed chiefly to the physical branches of the science—Pal�ontology and Historical Geology, which are very large subjects of themselves, having been only lightly touched upon.