Alternate Cold and Warm Periods.-Warm Inter-glacial Periods a Test of
Theories.-Reason why their Occurrence has not been hitherto recog-
nised. Instances of Warm Inter-glacial Periods.-Dranse, Dürnten,
Hoxne, Chapelhall, Craiglockhart, Leith-Walk, Redhall Quarry, Beith,
Crofthead, Kilmaurs, Sweden, Ohio, Cromer, Mundesley, &c., &c.—
Cave and River Deposits.-Occurrence of Arctic and Warm Animals
in some Beds accounted for.-Mr. Boyd Dawkins's Objections.--Oc-
currence of Southern Shells in Glacial Deposits.-Evidence of Warm
Inter-glacial Periods from Mineral Borings.-Striated Pavements.—
Reason why Inter-glacial Land-surfaces are so rare