INDEX TO VOLUME II. 



519 



Senescence, phenomena of, 186 

 Sensation, cutaneous, definition of, 390 



muscular, definition of, 390 



of after-pressure, 394 



of light, mechanism for the production of, 



331 

 of temperature, 3!»7 

 Sense of equilibrium, 404 



of touch, 392 

 Sensory areas of the cortex, determination of, 

 253 

 conducting paths in the spinal cord, 234 



continuation of, in the brain, 235 

 cortical areas in man, 255 



motor responses from, 253 

 relative functional importance of, 270 

 disturbance from hemisection of the cord, 230 

 impulses, path of, in the central nervous sys- 

 tem, 226 

 relation of, to the maintenance of the erect 

 posture, 419 

 nerve-endings in skeletal muscle, 402 

 in tendon, 402 

 in the skin, 391 

 nerves, rate of conduction in, 91 

 paths, degeneration of, after section of the 

 dorsal roots, 227 

 in the central nervous system, 226 

 regions of the cortex cerebri, 252 

 stimulation, relation of, to sleep, 291 

 Sex, characters of, 442 



of offspring, determination of, 483 

 origin of, 441 



relation of brain-weight to, 276 

 Sexual characters, 442 

 glands, accessory, 445 

 organs, 443 

 reproduction, 440 



congenital variations resulting from, 501 

 theory of origin of, 441 

 Shark, reflexes in, 212 



removal of cerebral hemispheres iu, 263 

 Shrapn ell's membrane, 365 

 Siamese twins, 483 



Simple muscular contraction, duration of, 102, 

 108 

 explanation of, 101 

 Simultaneous contrast, 347 

 Singing voice, 13 1 

 Size, increase of the embryo in, 487 



of nerve-cells, 175 

 Skiascopy, detection of astigmatism by means 



of, 319 

 Skin, tactile areas of, 395 



Sleep, 291 



cause of, 292 



condition of the pupils in, 325 



curve of intensity of, 294 



effects of loss of, 295 



responsiveness to stimuli in, 293 

 Smell, 108 



comparative physiology of, 409 



subjective sensations of, 410 

 Smooth muscle, rate of conduction in, 89 

 Snails, regeneration of lost parts in. i!tt> 



Somatic death, 191 

 Somatoplasm, definition of, 496 

 Somatopleure, 172 

 Sound, physical, 381 

 Sounds, quality of, 383 

 Sound-waves, amplitude of, 381 



composite, 384 



limits of perception of, -'I -0 -' 



production of, 381 

 Space illusions, 354 



Space-perception from visual sensations, :;it 

 Specific energies of nerves, doctrine of, 232, 399 



Specific energy of the optic nerve. 331 

 gravity of muscle, 159 

 of the encephalon, 275 

 of the nervous system at different ages, 28 I 



nerve-energy, doctrine of, 232, 399 

 Spectral colors, incomplete saturation of, 342 

 Spectrum, 332 



luminous intensity of the colors of, 340 

 top, Benham's, 31 1 

 Speech, dependence of, on hearing, 431 



elements of, 133 

 Speech-centre. 257 

 Spermatids, 445 

 Spermatocytes, 445 

 Spermatozoa, 1 lo 

 contractility of, 20 

 discovery of, 1 13, 498 

 entrance of, into the uterus, 465 

 locomotion of, 4<!5 

 maturation of, 445 

 movements of, 1 14 

 structure of, 113 

 Sperm-aster, 4U7 

 Sperm-nucleus, 466 

 Spermine, 4 15 

 Spherical aberration. 315 

 Sphincter ani, cerebral control of, 270 

 iridis, 325 



urethra-, contraction of, in erection, 464 

 Spinal cord, afferent paths of, 229 

 central neurones of, 203 

 degeneration of, from hemisection, 228 

 efferent neurones of, 203 

 motor tracts of, 2 15 

 reflexes in man, after section of, 213 

 schematic cross-sectiou of, 202 

 weight of, 271 

 ganglion-cells, development of, 178 

 nerve-roots, section of, 198 

 Spiral ganglion of the ear, 376 

 ligament of the cochlea, 379 

 Staircase contractions, 66, 112 



relation of, to tetanus, 124 

 Standing, 418 

 Stapedius muscle, 370 



stapes, :;<;7 



Starvation, effect of, on the nervous system, 289 

 static equilibrium, organs of, 107 

 Stature, relation of brain-weight to, 276 

 Stenson's experiment, 67 

 Stereoscope, 356 

 Sterno-hyoid muscle, 125 

 Sterno-thyroid muscle, 425 

 Stimulants, etfect of. on DQUSCUlar work, 75 

 Stimulation fatigue of noii-iucdullaled nerves, 

 l-o 



of the cortex, 241 

 Stimuli, chemical, of muscle. 131 



classification of. 23 



conditions determining efficiency of, 28 



effect Of Changing intensity of, 32 



of their repetition on irritability, 65 

 of varying b1 rengl h of, 39 

 galvanic, contracture effect of, in muscles, 131 



variat ions iu intensity Of, 31 



Strabismus, 300 



Stria' aCUSl ide, 237 



g] :i\ idaruin, 177 

 St r\ clmin. act ion of. on diffusion of impulses in 

 the cord. 217 

 on end-plates. 27 



on sympathetic ganglia, 219 



tetanus, 217 

 Stylo-hyoid muscle. 126 

 Stylonychia, reproduction of, 142 



Successive colli l\l-t. 346 



Sugar of muscles, L67 



