426 



ANIMAL AGGREGATIONS 



in Apis, 186 

 Oxygen tension, effect on sperm sus- 

 pensions, 269, 279, 280 

 in stream affected t)y mass of water 

 isopods, 194, 200 

 Oxytricha, 171 

 Oysters, 16, 36 



Packard, A. S., 330 



Palolo worms, 21 



Papanicolau, G., 304 



Paraffin, effect on contained organisms, 



125, 277 

 Paramecium, 12 



galvanotropic reactions, 39, 41 



trial and error reactions, 42 



trapped in acid, 61, 62 



growth inhibition, 107 



reproduction retarded by crowding 

 120, 136 



population cycle, 137 



allelocatalysis in, 167, 169, 170, 172, 



235 

 mass protection, from colloidal silver, 

 204 

 from methylyene blue, 212 

 from ultraviolet, 218, 220 

 culture medium, protects Procerodes 

 from hypotonic sea-water, 228 

 factors producing, 233 

 allelostasis in, 280 

 Paramermis, 301 



Parasites, of ants and myrmecocoles, 14 

 social, 35, 341, 342 



sex ratios affected by crowding, 290, 

 294, 299 

 Parasitism, Deegener's definition, 32 



relation to pro to taxis, 57 

 Park, R. E., 5 

 Park, T., 180 

 Parker, G. H., 81, 93 

 Parker, J. R., 331 



Parker, S. L., 131, 133, 135, 240, 241, 243 

 Parker, T. J., 291 

 Parrakeet flocks, 342 

 Passalid beetles, auditory integration, 92 

 Patangia, see Grasshoppers 

 Patrogynopaedium, 19, 24 

 Patropaedium, 25, 26 

 Pawlow, P. N., 214, 215 

 Pearl, R., 116, 126, 127, 128, 129, 130, 

 131, 133) 135, 240, 241, 242, 243, 

 244, 245, 280 



Pearse, A. S., 89, 117 



Pearson, J. F. W., 78 



Peck-order in bird flocks, 344 



Peebles, F., 117, 118, 119, 153, 154, 155 



Penfold, W. J., 250, 251 



Pentatomid bug attacks beetle larvae, 



245 

 Periodicities, lunar, in breeding behavior, 



69 

 Peskett, G. L., 167, 169, 170, 252 

 Petersen, W., 170, 171, 172, 173, 174, 175, 



176, 177, 178, 180, 218, 235 

 Pfeffer, W., 272 



pH, relation to autodestruction, 141, 142 

 affected by mass of water isopods, 194, 



200 

 relation to mass protection from hy- 

 potonic sea-water, 233 

 in sperm suspensions, 267, 284 

 Phalangidae, synchronous behavior, 88 

 Phase theory of locust forms, 316, 322 



experimental evidence, 327 

 Phases of bacterial cultures, 247 

 Phillips, E. F., 70 

 Phillips, J. F. v., 349 

 Phototropic reactions leading to aggrega- 

 tions, 38, 74, 181 

 of A sella s, 199 

 Phyla of animals, 356 

 Pickering, S., 103 

 Pieron, H., 203 



Pigeons, voice in social control, 95 

 Pinnotheres, in mantle cavity of Mytilus, 



32 

 Phylloxera, see Aphids 

 Physa, protection from colloidal silver, 

 210 

 excretions and male production in 

 Cladocera, 305 



Plague, locust, 321 



Planar ia, 12, 362 



growth limited by crowding, 113 

 autodestruction in KCl, 141 

 protection, from colloidal silver, 202, 

 203, 204, 205, 210, 211 

 from ultra-violet, 218 

 from distilled water, 225 

 protect Procerodes from hypotonic sea- 

 water, 230 

 killed by KCl, 274 



excretions affect male production in 

 Cladocera, 305 



