294 
Sondheim, M., 216, intelligence of 
damsel-fly, larvae, 191, 
192 
Spallanzani, Abbe, clasping instinct 
of brainless male frog, 106 
Sparrows, fear in, 122 
Spaulding, D. A., 114, instincts of 
chicks, 99 
Spaulding, E. G., 190, learning in 
hermit crabs, 186, 187 
Spence, W. See Kirby. 
Spencer, H., 10, 114, 138, 179, 
definition of instinct, 91, 
107 
Lamarckian theory of instinct, 
127 
mental evolution, 1, 9 
origin of instinct, 116, 117 
pleasure and pain, 167, 172- 
175 
relation of intelligence to other 
activities, 139 
Spider crabs, instincts for disguise- 
ment, 104 
Spiders, devouring their eggs, 96 
geotaxis, 32 
instincts of young, 98 
Spirillum, chemotaxis, 27 
geotaxis, 29 
Spirostomum, geotaxis, 30 
Stahl, E., chemotaxis in myxomy- 
cetes, 23 
Staphylococcus, attracting leu- 
cocytes, 26 
Starfish, habit formation, 154-155, 
158 
Statkewitsch, P., reaction of Para- 
meecium to induction 
shocks, 144 
Statocysts, functions of in crusta- 
cea, 31 
function in Ctenophores, 30 
Stentor, effect of hunger on, 150 
modifiability of behavior, 49, 
82-86, 141, 145, 150 
phototaxis, 44, 49, 82 
INDEX 
Stentor, reactions, 15, 81-86 
rhythms, 16 
Stereotropism, 33 ff, 42 
Stickleback, intelligence, 226 
Stoichactis, varied reactions, 146 
Stone, intelligence of dog, 250, 251 
Strasburger, E., 62, effect of tem- 
perature on phototaxis of 
swarm spores, 49 
Sunfish, intelligence, 223 
Surface tension theory of move- 
ments of Amceba, 67 
Swallows, instinct of flight, 97 
Swarm spores, change of photo- 
taxis, 47 
Talorchestia, photokinesis, 42 
phototaxis, 42, 54 
Temora, phototaxis changed by 
contact, 50 
Temperature, effect on phototaxis, 
49 
reactions of organisms to, 58, 
59 
Terns, fear in, 96, 97 
feigning death, 96, 97 
undefined instinct of young, 96 
Thermotaxis, 58, 59 
in Paramececium, 58, 75 
in Planaria, 59 
Thigmotaxis, 33-36, 42 
Thompson-Seton, E., 258 
Thorndike, E. L., 231, 258, 279, 
animal intelligence,nature 
of, 235-242, 251, 252, 255 
imitation in monkeys, 270 
intelligence in cats, 166, 167 
intelligence of monkeys, 261, 
262 
Titchner, E. B., 10 _ 
Toads, intelligence, 227, 228 
Toenjies, H., 258 
Torelle, E., 62 
Torrey, H. B., effect of hunger on 
food reactions of Sagartia, 
150 
