INDEX 



Oakley, K. P., 192 



Oaks, foliage of, 51 



Obelia, 136 



Ocean, ecological zones of, 19-21 



Octopus, 142 



Oenothera, 283-287 



genetics of, 283-287 



mutation in, 83 



tetraploids, 294-296 

 Oligocene Epoch, 64 

 Oligochaeta, 143 

 Onychopliora, 146-147 



annelid characters of, 146 



artliropod characters of, 146 



taxonomy of, 146-147 

 Oogamy, 106 

 Oogonia, 107 



Oparin, A. I., 92, 93, 97, 99, 110 

 Opossum, 273 

 Oppenheimer, Jane, 53 

 Orangutan, 18, 181 



appendix of, 42 



blood groups of, 59 

 Order, defined, 28 

 Ordovician Period, 65 

 Oreopitliecus, 184-185 

 Organic compounds, origin of, 93-94 

 Orient, islands of, 21 

 Oriental Region, 18 

 Origin of Species, 8-10, 54, 79 

 Osborn, H. F., 83 

 Oscaniiis, distasteful, 247 

 Osteichthyes, 160-166 



origin of, 161 



vertebrae of, 33 

 Ostracoderms, 159, 162 

 Ostrich, use of wings, 44 

 Owl, nictitating membrane of, 43 

 Oyster, 4 



Pachytene, 283 



Palearctic Region, 18 



Paleocene Epoch, 64 



Paleogijrinus, 164 



Paleontology, as evidence for evolution, 



62-74 

 Paleotheriidae, 72, 74 

 Paleozoic Era, 63, 65, 1 1 1 



duration of, 66 

 Van, 180 

 Panama, 21 



Istlimus of, 18 

 Pangenesis, theory of, 79 

 Papilio, and isolation, 227 

 Paraliip))iis, 74 

 Parainacium, 131 

 Parapitlwcus, 183 

 Parasitism, origin of, 96 

 Parazoa, 133-134 

 Pariah, 266 



PaHula, genetic drift in, 309 

 Parus, mimicry in, 246 

 Passenger pigeon, 332 

 Passerifonnes, 28 

 Pasteur, L., 90 

 Pearson, Karl, 82 

 Pectoralis, fused muscles, 153 



Pelagic zone, 21 

 Pelycosauria, 172 

 Penguin, wing of, 44 

 Penicillin, 333 

 PennsyKanian Period, 65 

 Peptide linkage, 94 

 Period, geological, defined, 63 

 Peripatus, 146-147 

 Perissodactyla, 176 

 Permian Period, 65 



date of, 66 

 Peromtjscus, 248, 273, 274 

 Petersen, 276 

 Petrifaction, 69 

 Petrified forest, 69 

 Phaeophyta, 101 

 Phalanges, 39 



Phalarope, and sexual selection, 249 

 Phenacomtjs, 273 

 Pholidota, 176 

 Phoronida, 147 

 Phosphagens, 59-60 

 Photosynthesis, 97 

 Phycocyanin, 102 

 Phylogeny, of animals, diagrammed, 150 



of bacteria, 99-100 



of lower invertebrates, 138 



of plants, diagrammed, 125 

 Phylum, defined, 28 

 Physiology, comparative, 54-61 

 Picidae, 28 

 Picifomies, 28 

 Pictet, A., 274 

 Piltdo'wn fraud, 191-192 

 Pineal eye, 44-45 

 Pineal gland, 44-45 

 Pisaster, 4 

 Pisces, 159-166 

 Pithecanthropus, 188-191 



characteristics of, 189 

 Placenta, 174 

 Placodenni, 159-160, 162 

 Placoid scales, 160 

 Planaria, 139 

 Plane tree. See Platanus 

 Plant breeding, 331,332 

 Plant Kingdom, 89 

 Plantae, 104 



Plants and animals, differentiated, 102 

 Plants, and serology, 58-59 



evolution of, 124-127 



main evolutionary trends of, 126-127 



flowering. See Angiosi^enns 



vascular, 113-127 

 origin of, 114, 125 

 Planula lar\ a, 135 

 Plasmodium, 130 

 Platanus, 272, 290-291 

 Platyhebninthes, 138 

 Pleiotropic genes, 251 

 Pleistocene dating, 191 

 Pleistocene Epoch, 64 

 Plesiadapidae, 182 

 Plesiosaurs, 168, 169 

 Pleurocentrum, 33, 35, 165 

 J^lioeene Epoch, 64 

 Pliohippus, 73, 74 



348 



