-CONTENTS 



Page 



of heat Fatigue Relation of stimulated area to sen 

 sation Perception of difference Relatively insensitive 

 regions* 

 SENSATIONS OF PRESSURE .......... 393 



Pressure spots Threshold value Touch discrimina- 

 tion Weber's law After-sensation of pressure 

 Temperature and pressure Touch illusion ; Aristotle's 

 experiment. 



GENERAL SENSATIONS 



TICKLE ........ ..... ,. . fc 898 



Irradiation After image Topography Summation 

 Fatigue. 



PAIN .......... ....... 399 



Threshold value Latent period Summation Topog- 

 raphyIndividual variation Temperature stimuli. 



MOTOR SENSATIONS .' ........... 400 



Judgment of weight Sensation of effort Sensation of 

 motion. 



vn 



TASTE 



TASTE ................. 401 



Threshold value Topography Relation of taste <to area 

 stimulated Electrical stimulation. 



VIII 

 INTRODUCTION TO PHYSIOLOGICAL OPTICS 



REFLECTION FROM PLANE MIRRORS 403 



Angles of incidence and reflection. 



REFLECTION FROM CONCAVE MIRRORS 405 



Principal focus Conjugate foci Virtual image Con- 

 struction of image from concave mirrors. 



