INDEX 



Activity, mental, optimum temperature 

 for, 172 



physical, optimum temperature for, 

 172 

 Adelochordates, 117 

 Africans, 148, 149 

 Agriculture, 153, 154, 177, 178, 180 

 Air currents, changes in, 73 

 Alaska, coal in, 155 

 Alchemists, 82, 95 

 Algae, 63, 113 

 Allantois, 126, 128 

 Allen, F. J., 101 

 Allosaurus, 133 

 a Centauri, 7, 8 

 Alps, rise of, 74 

 Alumina, 100 



Alveolar substance, of protoplasm, 83 

 Amblypods, 134, 136 

 American Indians, 148, 151, 153, 177 

 Amino acids, 85 

 Ammonia, 99, 102 

 Ammonites, 73 

 Ammonium carbonates, 107 

 Amnion, 126, 128 

 Amphibia, 125 



origin of, 65, 111 

 Amphtoxus, 117 

 Animals, domestic, 177, 178 



lime-secreting, 113 



wild, taming of, 177 

 Ankylosaurs, 132 

 Annelids, 113 

 Apes, anthropoid, 139, 141 



origin of. 111 

 Appalachian Mts., 78 



revolution. 111, 127 



trough, 78 

 Arabians, 150 



Arboreal habitat, forsaking of, for 



terrestrial, 142 

 Archaeocyathinae, 113 

 Archaopteryx, 129, frontispiece 

 Archean, beginning of, 43 

 Archeozoic era, 46, 49, 50, 56, 63 



era, time ratio of, 69 



sediments, thickness of, 63, 67 

 Arctic climate, effect of, on man, 149 

 Aridity, 123, 126, 127, 129, 136 



Devonian, 143 



Miocene, 143, 146 



Mississippian, 145 



Permian, 145 



Pliocene, 143 

 Aristotle, 86, 89, 91 

 Arrhenius, S., 97, 98 

 Arthropods, 114 

 Asia, as home of domestic animals, 178 



as primitive home of man, 149 



as' theater of mammalian evolution, 

 142 

 Asteroids, see planetoids 

 Asthenosphere, 41 

 Athenians, 147 

 Atmosphere, 54, 57, 75, 80 



in Archeozoic, 63 



of growing earth, 51 



of water-gas, 35 



origin of, 50 



primordial, 34 « 



Atmospheric blanket, of earth, 54 

 Atoms, 100, 101, 102 

 Australians, native, 150 

 Azoic era, time ratio of, 69 



Bacteria, 96, 97 

 Baker, H., 91 

 Balanoglossus, 117 



