of plants and alterations of snow line, [516]
of plants due to changes of climate, [517]
of plants from north to south, long continued, [518]
of plants aided by geological changes, [519]
of plants by way of the Andes, [520]
of plants by way of Himalayas and South Asia, [523]
of plants through Africa, [524]
Mild Arctic climates, stratigraphical evidence of, [187]
causes of, [190]
dependent on geographical changes, [191]