Civilization, distribution of, 173 



evolution of, 147, 174 



high, areas of, 188 

 Civilizations, early, 179 

 Clarke, F. W., 52, 54, 56 

 Climate, arctic, effect of, on man, 149 



as factor in racial differences, 148 



changes in, 53, 78, 80, 111 



changes in, as cause of extinction, 

 131 



changes in, causes of, 187 



changes in, effects of, 187 



changes in, evidences for, 184, 185 



changes in, historical, 183, 186 



Cretaceous, 55, 132 



effect of, on clothing, 154 



effect of, on death-rate, 158 



effect of, on discovery of use of fire, 

 175 



effect of, on energy, 156 



effect of, on food, 154 



effect of, on man, 153 



effect of, on materials for shelter, 

 154 



effect of, on Roman history, 190 



Eocene, 55 



Liassic, 55 



Permian, 51, 55, 127, 129, 145 



Pleistocene, 55, 66, 110 



Proterozoic, 51, 55 



Silurian, 55 



Triassic, 55 



tropical, effect of, on man, 149 

 Climates, ancient, 51, 52, 55 



glacial, 55, 66, 73, 110, 127, 143 

 Climographs, 159-161, 168, 169 

 Clothing, dependence of, on climate, 

 154 



effect of, on energy, 156 



necessitated by Glacial period, 143 

 Coal, 65, 66, 155, 174 

 Coelenterates, 113, 114 

 Cold, increase in, influence of, 127 



INDEX 197 



Collisions, among planetary nuclei, 33 



among stars, 23 

 Colloidal suspension, life elements in, 



106 

 Colloids, 100, 101 



characteristics of, 101 

 Comanchian period, 46, 76, 79, 111, 



131, 145 



Communal life, 144 

 Complexification, in matter, 100 

 Complexity, law of, 101 

 Condylarths, 134, 136 

 Conglomerates, 58 

 Conifers, 65, 73 



Connecticut Valley footprints, 130 

 Continents, areal variability of, 78 



elevation of, 71, 73, 75, 136 



in Archeozoic, 63 



origin of, 49 



permanency of, 50 



when largest, 73, 76 

 Convection currents, 35, 37 

 Coordination, biochemical, 106 

 Corals, 114 

 Coryphodon, 136 

 Cosmic time, 46, 47 

 Cosmozoa theory, 95 

 Crabs, land, 120 

 Creator, 108 

 Creodonts, 135 



Cretaceous period, 46, 76, 79, 111, 132, 

 145 



period, climate of, 55, 132 



period, in North America, 77 

 Critical periods, 73, 81 

 Crocodiles, 131 

 Croixian period, 76 

 Crops, of early Americans, 154 

 Crossopterygii, 122 

 Crust of earth, granitic, 34 

 Crustaceans, 120 

 Crustal density, relation of, to ocean 



basins, 39 

 Crystallization, fractional, 37 



