theory supported by rifts in polar cap, [329];
most satisfactory explanation of phenomena of canals, [339], [341], [344],
two seasons of growth of, [346];
melts snow, [328].
Water, dearth of, [128], [161], [163], [166], [168], [169], [341], [366];
loss of, inevitable, [131];
speed of flow of, [375];
from polar caps, [340], [374].
Water-vapor, from polar caps, [83];