CHAPTER III.

2. /Physiological Characters/ 105

_Functions of nutrition and assimilation_: Digestion, alimentation, growth, temperature of the body, etc.--_Respiration and circulation_: Pulse, composition of the blood, etc.--Special odour--_Functions of communication_: Expression of the emotions, acuteness of the senses, etc.--_Functions of reproduction_: Menstruation, menopause, increase in the number of conceptions according to season, etc.--_Influence of environment_: Acclimatation--Cosmopolitanism of the genus _Homo_ and the races of mankind--Cross-breeding.

3. /Psychological and Pathological Characters/.--Difficulties of studying them--Immunities--Nervous diseases of uncivilised peoples.