INDEX 



447 



Respiratory centre in medulla oblon- 



gata, 176, 178, 182 

 Respiratory quotient, 174 

 Retina, structure, 374 

 Retinal pigment, relation to vision, 381 

 Rice ordeal, arrest of secretion of 



saliva, 112 

 Rigor mortis, 266 

 Rods and cones, respective functions in 



vision, 378 

 Rowing, value of, as exercise, 287 



Saccharin, taste of, 367 

 Saline frog, respiration in, 193 

 Saliva, chemical constitution, 107 



function of, 96, 107 



Salivary glands, mechanism of secre- 

 tion, 108 



nerves of, 109, 236 

 Salts, absorption of, in alimentary 



canal, 128 



Scientific method, definition of, 71 

 Scratch reflex, in dog, 330 

 Sea-sickness, 106 

 Secretin, hormone of pancreas and liver, 



127 

 Secretion, accumulation of granules in 



cells, and their discharge, 110 

 a response to stimulation, 111 

 not a process of filtration, 110 

 Semicircular canals, their functions, 410 



their positions in space, 335 

 Sensations, their apparent fusion, 356 

 many which escape attention, 318, 



355 

 neutralization of one by another, 



356 



Sense-organs, origin in vertebrata, 336 

 Sensory areas in cortex of the great 



brain, 348 

 Sensory nerves, their connection with 



cerebro -spinal axis, 304 

 Shell-fish, poisonous extract of, 41 

 Shivering due to loss of heat from skin, 



257 



Sight. Cf. yision 

 Skate, electric organs of, 289 

 Skilled movements, dependent upon 



kinsesthetic sensations, 357 

 Skin, experiment of cutting nerve, 424 



variety of sensations from, 423 

 Sleep, condition of neurones in, 362 

 Sleeping sickness, 33 

 Smallpox, protection against, 78 

 Smell, disappearance of sense of, in later 



life, 370 



dog's dependence upon sense of, 366 

 reason for mental associations with 



sensations of, 371 

 sensitiveness to mercaptan, 365 

 Smells, nice and nasty, 369 



Smoking, mental effect of, 371 

 Sneezing on looking at bright light, 317 

 Sore-throat, cause of deafness, 412 

 Soul, Aristotle's definition, 32 

 Sound, mode of conduction, 404 



rapidity of vibrations of, 406, 418 

 Sounds of the heart, 228 



periodic and aperiodic, 409 

 Spectacles, defects of eyeball which call 



for, 392 



Speech, derangements of, due to disease 

 of the brain, 353 



mechanism of, 437 



Sphygmographs for recording pulse, 245 

 Spinal dog, reflex action in, 330 



frog, reflex action in, 307 



ganglia, development of cells, 299 

 Splanchnic nerves, regulation of blood - 



pressure by, 236 



Spleen, destruction of blood -corpuscles 

 in, 80 



structure, 79 

 Squint, correction of double vision in, 



397 



Starch, formula, 15 



Star-shapes due to puckering of crys- 

 talline lens, 393 

 Starvation, statistics of, 156 

 Stiffness of muscles, cause of, 45, 271, 

 Stimuli to muscles and nerves, 248 

 Stokes, discovery of spectrum of blood, 



68 

 Stomach, digestion in, 120 



glands of, 123 



referred pains from, 316 



shape and size, 99 

 Stone in the bladder, its cause, 213 

 Subconscious self, 355 

 Sugars, digestion of, 120, 136 



formulae, 15 



Sun, apparent size near horizon, 399 

 Suprarenal capsules, their structure and 



function, 91 



Sweetbread as article of diet, 215 

 Sympathetic system of nerves, 243, 325 



diameter of fibres, 325 

 Synapses of nerve-cells, resistance inter- 

 posed at, 306 



Synaptases, constructive ferments, 18 

 Synthesis by plants, 15 



Tapeworms, resist digestion in the in- 

 testines, 21 



Taste, confusion with sense of smell, 364 

 localization on tongue, 367 

 sense of, in fishes, 365 

 sensitiveness to quinine, 369 



Taste-bulbs, their structure, 368 



Tattooing, removal of pigment by leuco- 

 cytes, 55 



Tea, its dietetic value, 122 



