448 



THE BODY AT WORK 



Teeth, 96 



Tendon, the growth of, from cells, 28 

 Tension of gases in the lungs, 190 

 Tetanus, the vibratile contraction of 



muscle, 279 

 Thoracic duct, discharges lymph into 



veins, 43, 131 



Thorax, negative pressure in, 222 

 Thorns on dendrites of nerve-cells, 300 

 Thyroid body or gland, forms an in- 

 ternal secretion, 86 

 relation to goitre, 85 

 structure of, 85 

 Tight-lacing, deformation of organs 



which it causes, 220 

 Tigroids, in nerve-cells, stores of energy, 



320 



Tissues, respiration in, 165, 193 

 Tone of muscles, 272 

 Tongue, as organ of taste, 367 

 Tonsils, function as guardians of the 



fauces, 53 

 structure, 52 



Torpedo, electric organs of, 290 

 Touch, sensations of, 426 

 Toxins produced by microbes, 20 



Urea, amount relatively to proteins 



consumed, 155 

 antecedents of, 146, 212 

 chemical formula, 211 

 secreted during period of starva- 

 tion, 156 



Uric acid, amount secreted daily, 213 

 artificial production of, 13 

 chemical formula, 13, 214 

 diathesis, its relation to diet, 



140 



due to metabolism of leuco- 

 cytes, 53, 216 



form in which excreted, 207 

 made in the liver of birds, 13 

 Urticaria due to abnormal composition 

 of lymph, 41 



Vaccination, protective value of, 22 

 Valves of heart, their mechanism, 226 



Vascular system, tone of, 236, 240 

 Vaso-constrictor nerves, 236 

 Vaso-dilator nerves, 236 

 Vegetables, dietetic value of, 139 



digestion of, 125, 137 

 Vermiform appendix, 88 

 Villi of intestine, absorption of food 



by, 130 



fat seen in, during active di- 

 gestion, 134 

 Viscera, their insensitiveness to injury, 



316, 426 



Vision, colour contrasts, 382 

 duration of images, 382 

 judgment of distance and size, 411 



solidity, 401 



stereoscopic, doctrine of corre- 

 sponding points, 397 

 Visual purple, 381 

 Vital action, definition of expression, 



205 



Vivisection, 4 

 Vocal cords, structure, 431 



how modified in singing, 435 

 Voice, breaking of, in boys, 434 

 falsetto, how produced, 435 

 range of human, 435 

 registers, 436 

 Vomiting, 105 

 Vowels, synthesis by tuning-forks, 439 



Wandering cells, 33 



Warmth, appreciation of, by skin, 429 



Waste substances, classification, 194 



how eliminated from body, 59 

 Waterfall, negative after-image of, 384 

 Water -weed, experiment proving that 



it respires, 24 



Wear and tear of bioplasm, 145 

 Wisdom-tooth, tending to disappear, 96 



Yawning, beneficial effect on circula- 

 tion, 222 



nervous mechanism of, 180 

 Young's theory of col our -vision, 385 



Zymogen, 110 



THE END 



BILLING AND SONS, LTD., PRINTERS, OUILDFORD 



