x CONTENTS 



Hearing .......... . 345 



The Transmitting Apparatus and Functions of the Ear . 347 



The Organs of Corti .348 



How Does the Organ of Corti Act? . . 348 



Certain Qualities of Sounds ... . 350 



The Perception of Obstructions . . 351 



Touch, Pressure, and Location . 351 



Organs and Functions . . . .351 



Touch-spots ... . 355 



Certain Tactual Qualities . . . 355 



Taste .... .357 



The Gustatory Apparatus . 359 



The Taste-buds . . 359 



The Nerves of the Sense of Taste . 359 



Some Characteristics of Taste . . 360 



Smell .361 



The Olfactory Apparatus . . 361 



The Olfactory Cells . .361 



The Regio Olfactoria . . 362 



The Nerves of Smell . . , 363 



Some Conditions of Smell . . 363 



The Temperature-senses . . 364 



The Apparatus of the Temperature-senses . . 364 



Pain .... . .366 



The Sensory Apparatus of Pain . . 367 



Pleasure . . 369 



Vertigo . . 369 



Fatigue, Thirst, 'and Hunger . . 370 



Fatigue . . 370 



Thirst . . 371 



Hunger . . . 372 



Nausea . ... .372 



CHAPTER XI. 

 MUSCULAR ACTION. 



The Contractile System in Man . . 374 



The Structure of Muscle . 376 



Smooth Muscle . . . . 377 



Cross-striated Muscle. . 378 



Cardiac Muscle . 382 



The Chemistry of Muscle . . 382 



The Modes of Action of Muscle 383 



The Thermo-dynamic Theory . 384 



The Chemi-surf ace-tension Theory . 386 



The Neuro-muscular Mechanism 387 



Special Muscular Functions . 390 



Posture . 390 



Standing . 391 



Sitting . 



Locomotion . . 



Walking and Runaing . . . 392 



