Index 



875 



Insects, oxygen consumption in, 233 

 during flight, 238 

 phonoreception in, 492-499 

 respiration in, 264 

 respiratory responses in, 266 

 restricted diets in, 136 

 temperature "sense" in, 357 

 thermoreception in, 358 

 tracheae in, 223 

 tynipaiiiC oigans in, function, 495 



morphology, 493 

 uricolytic enzymes in, 204, 205 

 vitamin requirements of, 125 

 wood, nutrition of, 172 

 Inspiration, 254 



InsuHn, efEect on carbohydrate metabolism, 

 757 

 growth and, 727 

 Integument, as respiratory mechanism, 



211. See also Skin. 

 Intensity of sound, discrimination of, 482 

 Intestines, respiration through, 218 

 Invertase, 174 



Invertebrates, anaerobiosis in, 273 

 blood pressure in, 540 

 buffering in, 333 



carbon dioxide content of blood in, 330 

 cephalic dominance in, 816 

 cheraoreception in, 448 

 ganglionic function in, 812 

 gonadotropic hormonal activity in, 754 

 hemoglobin function in, 320 

 hormones in, growth and 729 

 metabolism and, 759 

 secondary and accessory sex charac- 

 ters and, 752 

 ions in body fluids in, 78 

 marine, nitrogen excretion in, 191, 192 

 muscles in, 583 



optic nerve discharge patterns in, 430 

 pH of digestive fluids in, 154 

 respiratory characteristics of blood of, 



308 

 secretion of digestive fluids in, 157 

 serological relations among, 107 

 site of digestion in, 150 

 See also Annelids, Arthwpods, Coelen- 

 terates, etc. 

 Iodine, permeability to, in crabs, 24, 25 

 lodopsin, 395, 397, 411 

 Ionic regulation, 80-84 



active absorption and, 91 



excretion and, 92 



mechanisms of, 90-94 



physical factors in, 90 



responses to alterations in medium, 



84-90 

 summary of, 97 

 Ions, inorganic, 75-102 

 balance of, 94 



Ions, inorganic, concentration in urine and 

 plasma, 93 

 in sea water and body fluids, 78 

 in tissues and body fluids, 75 

 ratios of concentration, 82 

 See also specific substances. 

 Iridocytes, 681 

 Iridosomes, 711 



Iris cells, primary and secondary, 388 

 Iron content of hemoglobin, 296 

 Isoleucine, structural formula, 118 

 Isopods, oxygen consumption in, 239 

 respiratory mechanisms in, 215 

 water loss in, 57 

 Isotonicity, definition, 6 



Jellyfish, muscle responses in, 595 



osmotic adjustment in, 14 

 Johnston's organ, 509 



Kidney, amphibian, 54 



effect on blood pressure, 761 



in birds, 58 



in crayfish, 30 



in elasmobranchs, 51 



in fresh-water fish, 47 



in mariile fish, 48 



in molluscs, 36 



in vertebrates, 48 

 Killifish, 49 

 Kinesis, 381 

 KHnokinesis, 387, 449 

 Klinotaxis, 383, 385, 449 

 Krause, bulbs of, 364 

 Krebs cycle, 188 



Krogh's method of measurement of os- 

 motic pressure, 8 

 Kynurenin, 730 



Laby'rinth in vertebrates, 483 

 functions of, 516 

 osseous, 474 



Labyrinthectomy, effects of, 520 



Lactation, 748 



Lactic acid tolerance in diving mammals, 

 260 



Lactogens, 748 



Lagena, 483 



Lakes, salt, osmoregulation to life in, 32 



Lateral line organs, 486, 507 



Leander, giant fibers in, 788 

 gonadotropic hormone in, 754 



Learning, 843. See also Conditioned re- 

 sponses. 



Leech, chromatophores in, 688 

 osmoregulation in, 36 



Leg movements in insects, 814 



Lemaecocera hranchialis, blood in, 22 



Lepidoptera, developmental hormones in, 

 735 



