CONTENTS 



PART I 



By M. M. Knight, Ph.D. 



The New Biology and the Sex Problem in 



Society 



CHAPTER PAGE 



I. The Problem Defined ... 3 



What is sex ? A sexual and mixed reproduction. 

 Origin of sexual reproduction. Advantage of sex 

 in chance of survival. Germ and body cells. 

 Limitations of biology in social problems. Sex 

 always present in higher animals. Sex in mam- 

 mals — the problem in the human species. Appli- 

 cation of the laboratory method. 



TI. Sex in Terms of Internal Secretions 18 



Continuity of germ plasm. The sex chromo- 

 some. The internal secretions and the sex 

 complex. The male and the female type of 

 body. How removal of sex glands affects body 

 type. Sex determination. Share of the egg and 

 sperm in inheritance. The nature of sex — 

 sexual selection of little importance. The four 

 main types of secretory systems. Sex and sex 

 instincts of rats modified by surgery. Dual 

 basis for sex. Opposite sex basis in every indi- 

 vidual. The Free-Martin cattle. Partial re- 

 versal of sex in human species. 



III. Sex and Sex Differences as Ouanti- 57 

 tative ...... 



Intersexes in moths. Bird intersexes. Higher 

 metabolism of males. Quantitative difference 

 between sex factors. Old ideas of intersexuality. 

 Modern surgery and human intersexes. Quan- 

 titative theory a Mendelian explanation. Pecu- 

 liar complication in the case of man. Chemical 

 life-cycles of the sexes. Functional-reproductive 

 period and the sex problem. Relative signifi- 

 cance of physiological sex differences, 



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