CONTENTS. Ix 



Page 



CHAPTER VII. 



ON THE RACES OF MAN. 



The nature and value of specific characters— Application to the 

 races of man — Arguments in favor of, and opposed to, ranking 

 the so-called races of man as distinct species — Sub-species — Mon- 

 ogenists and polygenists— Convergence of character— Numerous 

 points of resemblance in body and mind between the most dis- 

 tinct races of man— The state of man when he first spread ovei 

 the earth — Each race not descended from a single pair— The ex- 

 tinction of races — The formation of races— The effects of crossing 

 — Slight influence of the direc* action of the conditions of life — 

 Slight or no influence of natural selection— SexuaJ selection 162 



PART II. 

 SEXUAL SELECTION. 



CHAPTER YIII. 



PRINCIPLES OP SEXUAL SELECTION. 



Secondary sexual characters — Sexual selection— Manner of action 

 -Excess of males— Polygamy — The male alone generally modified 

 through sexual selection— Eagerness of the male— Variability of 

 the male — Choice exerted by the female — Sexual compared with 

 natural selection— Inheritance at corresponding periods of life, 

 at corresponding seasons of the year, and as limited by sex — Re- 

 lations between the several forms of inheritance — Causes why one 

 sex and the young are not modified through sexual selection- 

 Supplement on the proportional numbers of the two sexes 

 throughout the animal kingdom — The proportion of the sexes in 

 relation to natural selection 203 



CHAPTER IX. 



SECONDARY SEXUAL CHARACTERS IN THE LOWER 

 CLASSES OP THE ANIMAL KINGDOM. 



These characters absent in the lowest classes— Brilliant colors — 

 MoUusca— Annelids— Crustacea, secondary sexual characters 

 strongly developed; dimorphism; color; characters not acquired 

 before maturity— Spiders, sexual colors of; stridulation by the 

 males— Myriapoda ■ 257 



CHAPTER X. 



SECONDARY SEXUAL CHARACTERS OP INSECTS. 



Diversified structures possessed by the males for seizing the fe- 

 males — Differences between the sexes, of which the meaning is 



