CONTENTS. 



Introduction Pages 1-26 



CIIAP. I. — General Principles of Expression. 



The three chief principles stated — The first principle — Serviceable ac- 

 tions become habitual in association with certain states of the mind, 

 and are performed whether or not of service in each particular case — 

 The force of habit— Inheritance — Associated habitual movements in 

 man — Keflex actions — Passage of habits into reflex actions — Asso- 

 ciated habitual movements in the lower animals — Concluding re- 

 marks 27-49 



CIIAP. II. — General Principles of Expression — continued. 



The Principle of Antithesis — Instances in the dog and cat — Origin of 

 the principle — Conventional signs — The principle of antithesis has 

 not arisen from opposite actions being consciously performed under 

 opposite impulses 50-65 



CHAP. III. — General Principles of Expression — concluded. 



The principle of the direct action of the excited nervous system on the 

 body, independently of the will and in part of habit — Change of 

 colour in the hair — Trembling of the muscles — Modified secretions — 

 Perspiration— Expression of extreme pain — Of rage, great joy, and 

 terror — Contrast between the emotions which cause and do not cause 

 expressive movements — Exciting and depressing states of the mind — 

 Summary 66-82 



CHAP. IV. — Means of Expression in Animals. 



The emission of sounds — Vocal sounds — Sounds otherwise produced— 

 Erection of the dermal appendages, hairs, feathers, &c, under the 

 emotions of anger and terror — The drawing back of the ears as a prep- 

 aration for fighting, and as an expression of anger — Erection of the 



ears and raising the head, a sign of attention 83-114 



iii 



