292 



INDEX 



Malinowski, B,, 213, 243 

 Man, 26; mass protection, 52, 

 85, 209; evolution of, 88; 

 effects of numbers on men- 

 tal work, 142; social rank- 

 ing, 201; war, 210; enemies 

 of, 240; castes, 251; com- 

 bativeness, 261 

 Manakin, breeding behavior, 



134 

 Mass protection, 52, 85 

 Mast, S. O., 81 

 Masure, R., 185, 192 

 May-flies, 35 

 Maze learning, 150; relation 



to social rank, 192 

 Metaphysics, 18 

 Mice, effect of numbers on 



rate of growth, 99; on rate 



of reproduction, 103 

 Migration, 33 

 Minnesota, experiments on 



class size, 145 

 Mixed flocks, leadership in, 



48, 197 

 Moina, sex determination, 



257 

 Murchison, C, 182 



Mutation, 118 



Newman, H. H., 206 

 Netherlands, population, 226, 



227 

 Nichols, J. T., 197 



Paramecium, 76 

 Park, Thomas, 105 

 Parrakeet, effect of numbers 



present on learning, 155; 



social order, 185, 191, 192 

 Patten, W., 27 

 Pearl, Raymond, 107, 216, 



218, 222, 223, 224 

 Peck-order, 176; relation to 



leadership, 199 

 Phases of grasshoppers, 272 

 Phillips, John, 107 

 Philosophy, 17, 23 

 Pigeons, social order, 186, 207 

 Planaria, mass protection, 59 

 Poisons, mass protection from, 



53' 56 



Poland, children in wartime, 

 230 



Popenoe and Johnson, 234 



Population, optimal size, 92, 

 103, 104, 125, 128, 130, 131; 

 minimal, 108; human, re- 

 lation to war, 214; of the 

 world, 215, 218; of U. S. A., 

 217; of various countries, 

 226 



Procerodes, mass protection, 



63 



Protozoa, effect of numbers 

 on rate of division, 76; ex- 

 planation of effect, 80; as- 

 sociated with termites, 270 



Pseudo-leadership, 197 



Oesting, R. B., 92 

 Overcrowding, 31, 50; effect 



on growth, 91, 103 

 Oxytricha, 77 



Quintuplets, Dionne, 201, 207 



Retzlaff, Elmer, 102 

 Robertson, T. B., 75 



