often of small amount in high latitudes, [135]

never perpetual on lowlands, [136]

conditions determining perpetual, [137]

maintains cold by reflecting the solar heat, [144]

Snow-line, alterations of, causing migration of plants, [516]

Sollas, Mr. J. W., on greater intensity of telluric action in past time, [223]

South Africa, recent glaciation of, [163]

many northern genera of plants in, [524]

its supposed connection with Australia, [525]

South American plants in New Zealand, [521]