Camera, the, 272; advantage of, 273; slower than the eye, 273; stars the peculiar province of, 273, 274. Canals, 11, 32, 163; discovery of, 24, 26; considered straits, 27; regularity of, 28, 29; unnatural in look, 173; manner of introduction of, 174; conditions necessary to seeing of, 174-177, 282, 283; pencil-like lines, 177, 179, 367; definite in direction, 178; name, 180; width of, 179, 180, 182; length of, 183; visible by virtue of length, 181; oddities of, 183; number of, 184; systematic arrangement of, 184, 185, 187-191, 248; connect with polar caps, 325, 339, 373; import of system of, 338, 372, 373; intrinsic change in, 283, 284, 337, 338; what they are not, 185-187, 373; zonal distribution of, 188, 189; departure-points, 190; dependent on general topography, 191; of later origin than main features, 191, 247; kinematic character of, 281-303; effect on, of illumination, 284; drawings of, numerous and consecutive, 286; coördination of data, 288, 289; curves of visibility of (see Cartouches), 289, 290; geometricism of, 175, 206, 365, 367, 368; polar, 327. Canals in the dark regions, 30, 31, 243-248; of the southern hemisphere, 245; of the northern hemisphere, 246, 247; detection of, 243, 245; deprived seas of marine character, 243; part of canal system, 244, 245, 247. Caps (see Polar Caps). Carbon dioxide, 39, 161, 164-168. Carbonic era of Earth, 134, 141, 142. Carets, 265-270; natural formations, 231, 232; form and position of, 266, 267; reason for shape of, 268; associated with canals, 267, 269; help in solution of riddle, 270; act like oases, 333. Cartouches of the canals, 289-303; interpretation of, 291-293, 299-303, 344-347; arranged by latitudes, 294; showing first frosts, 299; minimum points of, 297, 344; maximum point of, 301; mean canal, 297, 298. Cenozoic times, 144. _Cerberus_, obliterated by white spot, 75. Change, 4, 281; shown in polar caps, 37, 338; in blue-green areas, 113, 114, 115, 120, 122-127, 163, 164; in canals, 168, 169, 205, 283-285, 314, 337, 338; in oases, 250-252, 330, 331, 337, 338. Chromacea, 352; plasm-forming beings, 353; close to inorganic things, 357; in hot springs, 357, 358. _Chryse_, 90, 102. Climate, 82-89; one of extremes, 87; temperature, theoretic and observed, 87; non-glaciation the rule, 88. Clouds, 55, 71, 73, 89, 163, 165, 283, 284; but few exist, 83, 165; none over blue-green areas, 92; of tawny dust color, 106; probably dust storms, 165; prove existence of atmosphere, 167. Cold, 87, 167, 299. _Coloe Palus_, in connection with double canals, 257, 258, 263. Color, 74, 148; of Mare Erythraeum, 122. Confervæ, in almost boiling geysers, 349, 358.