470 



INDEX 



Patella, 145 



Peas, inheritance in, 272-282 



Pectoral girdle, 141, 144, 14$, 

 354 



Peduncle, 107 



Pelvic bones, 317, 144, 153 



Perca, 141, 148 



Perch, dissection, 148 



Pericardial cavity, 140 



Peripheral nervous system, 186 



Peristalsis, 157 



Peristome, 40 



Peritoneum, 59, 137 



Permian period, 358 



Perspiration, 176 



Petal, 75, 107, 108, 112 



Petiole, 71 



Phagocyte, 338 



Pharynx, 123, 152, 153, 155 



Phenotype, 275, 277, 279, 281 



Phloem, 60, 76, 81, 87 



Phosphates, 36 



Photosynthesis, 35, 87, 332; chem- 

 ical equation, 36 



Phylogeny, 364 



Physcia, 332 



Physical basis of life, 7-10, 400 



Physical sciences, 1 



Physics, origin of, 395 



Physiological division of labor 

 (see Division of labor) 



Physiologus, 383 



Physiology, 3, 4, 367; compara- 

 tive, 396; Flowering Plant, 84- 

 90; history, 394-398 



Pigeon, compared with Archaeop- 

 teryx, 360; brain, 189; dissec- 

 tion of, 151; domestic varieties, 

 373 



Pineal body, 187, 188, 189 



Pinna, 152, 198 



Pistil, 75, 107; compound, 108 



Pitcher-plant, 73 



Pith, 60, 76, 81, 87 



Pituitary body, 183, 447 



Placenta, 205 



Planaria, 223 



Plant, body, 61-90; classification, 

 413, 414; chromosome reduc- 

 tion, 228; colorless, 38; evolu- 

 tion, 105, 112-114; food, 397; 

 green, 30; gross structure, 65- 

 75; histology, 75-84; ideal 

 vertical section, 76; physiologi- 

 cal activities, 87; reproduction, 

 91-114; stem, 81; unicellular, 

 30, 39 



Plantigrade, 316 



Plasma, 163 



Plastid, 26, 27 



Plexus, nerve, 190, 191 



Pliny the Elder, 382 



Pliocene period, 358 



Polar body, 231, 233 



Polar lobe, 255 



Pole cells, 126 



Pollen, 110, 112; basket, 329; 

 brush, 326; combs, 329; grain, 

 108; tube, 109, 110 



Pollination, 111 



Polygon, frequency, 299-305 



Polyhybrid, 276 



Polymorphism, 218 



Polytrichum, 101 



Pond Scum, 92, 413 



Population and pure lines, 300 



Porpoise, 317, 416 



Portal vein, 150, 167, 168 



Porto Santo Rabbits, 369 



Potato, 66, 70 



Potential energy, 6, 15, 35, 42 



Precaval vein, 164 



Preformation, 253, 257, 259, 401, 

 406 



Pressure, 313 



Prickly Pear, 70 



