82 PHYSICAL EXPRESSION. 



CHAPTER VI. 



PHYSIOLOGY OF EXPRESSION. 



Modes of movement in plants ; in tlie amoeba ; the ascidian has 

 a nerve-mechanism, and apparatus for reflex movements 

 Nerve-mechanism of vertebrates Nerve-muscular apparatus ; 

 nerve-muscular action Do certain nerve-centres produce certain 

 movements ? Ferrier's experiments Cerebral localization 

 Nerve-centres Visual perception indicated by movements 

 Time requisite for a reflex movement Inhibition of move- 

 ment Physiological eifects of light, in man, in plants Light 

 stimulates trophic and kinetic action Effects of light in the 

 new-born infant; movements stimulated, inhibited, co-ordi- 

 nated Eetentiveness to effects of light The brain of an idiot 

 not thus impressionable to light Summary of the effects r of 

 light Extrinsic stimuli, mediate and immediate Trophic 

 action of light Summary of eifects of light on plants. 



IN dealing with the physiology of expression we 

 are concerned solely with facts in the history of 

 living beings, plants and animals, including man ; 

 the sections of physiology that we are mainly con- 

 cerned with are those involving questions of move- 

 ment and nutrition. It is convenient, then, to our 

 purpose that we should take a brief review of the 

 modes in which movement is produced in the 

 organism of the lower, and higher, living beings. 

 Something has been said in chap. ii. about the 



