1046 



Nerve-impulse, historical, 110 



metabolism during, 119 



modification of, by various influ- 

 ences, 115 



qualitative changes in, 82, 122 



relation of, to action current, 105, 

 114 



theories of, 120 



velocity of, HI 

 Nervi erigentes, 252, 608, 628 

 Nervous secretion, gastric, 772 



pancreatic, 787 

 Neurogenic theory of heart-beat, 563 



tonus, 56 

 Neuron doctrine, 129 

 Neurons, varieties of, 131 

 Nicotin, action of, on salivary secre- 

 tion, 757 

 on sweat secretion, 860 



use of, in tracing autonomic fibers, 

 250 

 Night-blindness, hemeralopia, 357 

 Ninhydrin reaction for protein, 1022 

 Ninth cranial nerve, nucleus of, 245 

 Nissl's granules, 134 

 Nitric oxid hemoglobin, 427 

 Nitrogen, condition of, in blood, 672 



deterinination of, 890 



.equiUbrium, 889 



effect of non-protein food on, 892 



excretion in urine, 841 

 Nitrogenous extractives of muscle, 64 

 Nodal point of eye, 308 

 Non-polarizable electrodes, 102 

 Non-protein nitrogen, 446 

 Norleucm, 790 

 Normoblasts, 437 

 Nuclease, 745 



Nucleo-albumin in bile, 814 

 Nucleoproteins, 1025 



in blood, 449 



intermediary metabolism of, 848 



Obesity, physiological cause of, 920 

 Ohm's law of composition of sound 



waves, 394 

 Olfaction, end-organ for, 295 



mechanism of, 296 

 Olfactometer, 300 

 Olfactory area, 215 

 associations, 301 



bulb, histological structure of, 214 

 center in cortex, 213 

 nerve, course of fibers of, in brain, 



215 

 organs, fatigue of, 299 

 sensations, classification of, 297 

 conflict of, 301 

 qualities of, 297 

 threshold stimulus, 299 

 sense cells, 296 



Olfactory, stimuli, nature of, 297 



Oncometer, 837 



Oocytin, 987 



Oogonia, 984 



Ophthalmometer, 330 



Ophthalmoscope, 327 



Opotherapy, 863 



Opsonins, 441 



Optic chiasma, decussation in, 208 



nerve, course of fibers of, in brain, 

 206 



radiation, 208 



thalamus, functions of, in vision, 

 209 



tracts, structure of, 208 

 Optical deceptions, 379 

 OptogBams on retina, 335 

 Orokinase, 760 

 Orthodiagram, 542 

 Orthodiagraph, 542 

 Osmosis, definition of, 1026 

 Osmotic pressure, definition of, 1027 

 determination of, 1029 

 of blood, 420 

 Oval field of Flechsig, 179 

 Ovaries, internal secretion of, 884 



relation of, to menstruation, 979 

 Overtones, production of, 394 

 Ovulation, 975 

 Ovrnn, fertilization of, 985 



implantation of, in uterus, 987 



maturation of, 983 



passage of, into uterus, 782 

 Oxalate solutions, effect of, on coagu- 

 lation, 465 

 Oxalated plasma, 462 

 Oxidases, 743, 967 

 Oxidations, theories of, 967 

 Oxygen, action of, on respiratory 

 center, 692, 701 



compound of, with hemoglobin, 426 



condition of, in blood, 672 



effects of varying pressures of, on 

 respiration, 701 



potassium ferricyanide method of 

 determining, 666 



tension of, in alveolar air, 677 

 in tissues, 679, 680 

 in venous blood, 677 

 Oxygen-pressure of blood, 681 

 Oxygenase, 970 

 Oxyhemoglobin, 426 

 Oxyprolin, 791, 1019 

 Oxyproteic acid, 843 

 Oxypurins, 847 

 Oxytocic action (pituitary), 879 



Pacchionian bodies of brain, 619 

 Pain sense, distribution and charac- 

 teristics of, 282 

 localization of, 283 



