234 INDEX 



Fishes (cont.) 



lateral line, i8, 180-1, 194; 

 barbels as organs of touch, 210- 

 1 1 ; sensory pits in sharks and 

 rays, 215; reaction to electric 

 currents, 216-17 



Flagellum, of Protozoa, 1 26 



Flies, their special hairs serving as 

 tongues, 109 



"Four-eyed Fish". See Anableps 



Foxes : short-sighted 65 ; hearing 

 75; scenting power, 106; sense 

 of taste 1 1 1 



Frogs, brain of, 135; sight: and 

 moving prey, 24, 135; observa- 

 tions and experiments 35-40 ; 

 climbing ability, 37-8; a pecu- 

 liar use of their eyes, 140; 

 HEARING : auditory sense 14-15 ; 

 importance of sound 71-2 ; func- 

 tion served by croaking 72, 

 77-8; field observations, 77; 

 smell: scenting powers, 91,102, 

 200 ; TOUCH : sensitivity over 

 whole body, 119; monitors : 

 homing ability 



Fruits eaten by lizards, 52 



Galagos. See Bush-babies 



Geckos, observations and experi- 

 ments on their sight, 49 



Geese, scenting power of, 19, 92 



Goldcrest, 81 



Gorillas, their sense of touch, 1 20 



Gosse, P. H., 128-30 



Grass Snake, experiment on its 

 sense of smell, 10 1-2 



Grasshoppers : stridulation, 7 1 ; 

 experiment on its hearing, 76-7 ; 

 auditory organs, 179 



Gravity-receptor, 219-20, 222 



Grayling, 26 



Great Warty Newt, 45 



Green Lizard, 47, 49, 5 1 , 52 



Greyhounds : sight, 28 ; scenting 

 power, 106 



Haddock, 21 1 



Halteres, of insects, 223 



Hares : eyesight and defence 28 ; 



hearing 75^ 85 

 Hawker Dragonflies, 16, 33-4 

 Hawks, 148 



Hearing, sense of: definition, 14, 

 169; and communication be- 

 tween animals, 69; response to 

 sounds, 69-70; more vital than 

 sight to some animals, 70 ; field 

 observations and experiments : larger 

 invertebrates, 76^7 ; amphibians, 

 77-8; reptiles, 78-80; birds, 80- 

 83; mammals, 84-8; — mechan- 

 ism and structure of the ear, 

 169-73; inner and middle ears, 

 174; structure of birds' ears, 

 174-6; location of direction of 

 sound, 175, 176; structure of 

 ears of reptiles, amphibians, 

 fishes, 177; comparison of verte- 

 brates and invertebrates, 1 78-9 ; 

 auditory organs of insects, 1 79- 

 80; and the sensilla of insects, 

 180; the lateral line in fishes, 

 1 80- 1 

 See also Echo-location 



Heat-receptor, 213 



Hedgehog: sight, 28; scenting 

 power, 107; sense of touch, 120 



Hedge-sparrows, 73 



Homing ability, 15, 225-6, 228 



Hornbills, eyelashes of, 140 



Horses, 85, 219 



Horseshoe bats, their use of sonar, 

 186 



Hounds, scenting power of, 104 



Hunger, proprioceptive reaction 

 to, 224 



Hydra : their limited sensory equip- 

 ment, 15-16, 128; experiment 

 to test sense of touch, 1 1 8 



Ichneumon flies, their sense of 

 touch, 1x8 



Infra-red radiation, detection of, 

 by pit- vipers, 215-16 



Insects : variations in dominant 

 senses, 16-17; sight: two kinds 

 of eyes, 23 ; field observations, 

 33-4; optical mechanism, 160- 

 167; colour vision, 167; hear- 

 ing : importance of, 71; stridu- 

 lation, 71 ; experiments on, 76- 

 77; auditory organs, 179-80; 

 smell: organs for detecting 

 scent, 90-1, 97, 201-3; field 

 observations and experiments, 



