378 



Index 



Chemicals, effect on phototropism, 203. 



Chick, 224, 229 f., 266, 268. 



Chlamydomonas, 178. 



Choice, as evidence of mind, 28. 



Chordotonal organs, 121 ff. 



Chromotropism, 148, 154. 



Cirripedia, 1-42. 



Clepsine, 139. 



Cockroach, 121, 264, 312. 



Coelenterates, chemical sense, 69 ff. ; 

 hearing, 116 f.; response to change of 

 light intensity, 136 ff. ; response to 

 color, 146; geotropism, 182 f. ; re- 

 spouse to motion, 215 f. 



Color vision, invertebrates, r44 ff. ; 

 amphioxus and fish, 159 ff. ; reptiles, 

 and amphibians, 163 ff. ; birds, 165 

 S. ; mammals, 169 fi. 



Common chemical sense, no. 



Communication in ants, 95 f. 



Compound eye, 217 ff., 241 f. 



Continuous action theory of tropisms, 

 194 ff. 



Contrast, isi f. 



Convoluta, 184, 201, 209, 315. 



Copepods, 8g, 189. 



Corymorpha, 71, 182. 



Cow, 291 f. 



Crab, 153, 231, 263, 273. 



Crayfish, 88, 152, 188 f., 217, 273. 



Cricket, 122 f. 



Crow, 299 f . 



Crustacea, chemical sense, 87 ff. ; hear- 

 ing, 118 f. ; response to change of 

 light intensity, 142; color vision, 

 149 f. ; geotropism, 188 f. ; 202 f. 

 See Crab, Crayfish, Hermit Crab. 



Ctenophors, 183. 



Cypridopsis, 204. 



Cypris, 204. 



Daphnia, 149 ff., 194, 201 ff. 



Delayed reactions, 242 f ., 302 ff., 318 f. 



Delayed Reaction Method, 290 f., 

 297 f. 



Density of water, effect on phototro- 

 pism, 202 f. 



Depth perception, 237 ff. 



Didiniiim, 69. 



Difficulties of comparative psychology, 

 rff. 



Dina, 139. 



Dinetus, 109. 



Direction of light, perception of, 220 f. 



Direction theory of tropism, 19s, 199 f- 

 Discrimination, evidence of, 54 ff. ; 



acquired by punishment, 264 ff. 

 Distance receptors, 303 f. 

 Distributed repetitions, 311. 

 Dog, 113, 133 f., 171, 227 f., 269 I., 



287 f. 

 Dragon fly, 252. 

 Dreaming in animals, 287 f . 

 Dropping out of movements, 258 ff. 

 Dysdera, 221. 

 Dytiscus, 91. 



Earthworm, 81 f., 117, 139, 146 f., 17s, 

 198 f., 223, 263, 273, 31S. 



Echinaster, 141 f. 



Echinoderms, chemical sense, 86; hear- 

 ing, 117; response to change of light 

 intensity, 141 f. ; color vision, 149. 

 See Starfish, Sea-urchins. 



Elberfeld horses, 308 f . 



Electric shock method, 265, ■' 



Eloactis, 137. 



Emotional adaptation, 255 f. 



Emotional aspect of maze running, 284. 



Errors, order of eliminating, 27s f. 



Euglena, 136, 178, 199. 



Evolutionary writers, attitude toward 

 animal mind, 15 f. 



Experiment, Method of, 9 ff. 



Fatigue, 60, 252 f., 255. 



Fear, effect on phototropism, 208. 



Fiddler crab, irg, 188, 208. 



Firefly, 298. 



Fish, chemical sense, 109 ff. ; hearing, 



126 ff. ; color discrimination, 160 ff. ; 



orientation to gravity, 190 ff . ; rheot- 



ropism, 212 ff. ; distance perception, 



238; learning, 259 f., 263, 273. 

 Flatworms, chemical sense, 78 ff. ; 



hearing, 117; photokinesis, 144; 



geotropism, 183; phototropism, 199; 



223, 249 f. 

 Form, visual perception of, 225 ff. 

 Frequency, 276. 

 Frog, III f., 130 f., 163 f., 223, 263, 274. 



Gelasimus, 119, 188, 208. 



Geodesimus, 80. 



Geotropism, in Protozoa, 178 ff. ;' in 

 coelenterates, 182 f. ; in planarians, 

 183 f. ; in mollusks, 185 f. ; in spiders 

 and insects, 189 f. ; in annelids, 184 f. ; 



