INDEX 



427 



crowding on growth form, 312 



abundance, 358 

 Plant toxins, effect on succession, 102 

 Plants, relation to black-bass food chain, 

 84 



competitors of black bass, 85 

 » Platypoeciliis, growth limited by crowd- 

 ing, 113 

 Pleurotricha, 167, 169 

 Plotnikov, V. I., 327, 328, 329 

 Plunkett, C. R., 332, ^s?, 

 Polenia, see Diptera 

 Polyandry, 26 

 Polygamy, 26, 348 

 Polygyny, 26 

 Polyspermy, 266 



Popovici-Baznosanu, A., m, no 147 

 148 



Population density, human, effect on 

 death-rate, 115, 142 

 effect on size, ii8 

 Drosophila, effect on reproduction, 132 



optimum for growth, 148 

 hookworms, optimum for growth, 135 

 general importance, 135 

 equilibrium in flour beetles, 138, 179 

 death-rate in scale insects and, 239 

 longevity in Drosophila and, 240 

 Population equilibrium, in beetles, 138, 

 179 



■ Portuguese-man-of-war, polymorphism, 

 23 

 Predators and prey, 31, 246 

 Prevost, J. L., 263 

 Prionyx, sleep aggregations, 75 

 Procerodes, formation of aggregations, 36 

 mass protection from hypotonic sea- 

 water, 223, 275 

 heterotypic protection against, 228 

 factors contributing, to 231 

 Promiscuity, sexual, examples, 27, 347, 

 356 



Protein, associated with growth promo- 

 tion, 150, 15s 



Prototaxis, 46 



Protozoa, 12, 14, 15, 362 

 colonial, 15, 16 

 sexual societies, 26 

 growing on other animals, 32 

 growth inhibition of, 107 

 rate of reproduction retarded by 

 crowding, 120 



volume affects rate of reproduction, 122 



allelocatalysis, 161, 250 



lag, 161, 248 



mass protection in, 204, 212, 218, 220 



culture cycle compared with bacteria, 



247 

 killed by KCl, 274 

 allelostasis in, 280 

 Pseiidomermis, see Nematodes 



"Psychological" influence of numbers, on 

 snails, no 

 on hens, 129, 245 



Quail, in dry season, 72 



Rabbits, signaling, 96 



sperm physiology, 282 

 Racing record, relation to length of 



course, 116 

 Rahn, O., 105, 251 

 Rana, breeding behavior, 68 



tadpoles, growth limited by crowding, 



112 

 regeneration rate increased by crowd- 

 ing, 148 

 mass protection from colloidal silver, 

 207 



Random movements, aggregations, due 

 to, 42 



Rau, N. and P., 75, 76, 80, 102 



Reaumur, R., 70, 



Reeves, C. D., 68 



Reflexes leading to Ameiunis aggrega- 

 tions, 64 



Regeneration, tadpoles, affected by 



crowding, 148 

 Reighard, J., 32, 68, 289, 345 

 Reinhard, H. J., 313, 314, 315 



Reproduction, retarding of by crowding, 

 120, 165, 304 



rate increased by crowding, 161 

 Reptilia, 12, 21, 27, 68, 70 



polyspermy, 266 



Resistance, electrical, of hypotonic sea- 

 water, 225 



Respiratory exchange, affected by crowd- 

 ing, 181, 184, 186, 192, 195, 198 



Respiratory rate in sperm suspensions, 

 267, 279 



Rettger, L. F., 249 



Rheotropism in Asellus, 56, 59 



Rhythms, lunar, in breeding behavior, 69 

 in social appetite, 80 



