CONTENTS 



Ctt\P. PAGE 



PREFACE V 



1 . THE GENETIC THEORY OF SEX-DETERMINATION I 



2. THE SEX-CHROMOSOMES AND SEX-DETERMINATION. 



THE SEX-RATIO 9 



3. SEX-LINKAGE. NON-DISJUNCTION. GYNANDRO- 



MORPHISM 18 



4. SEX-DETERMINATION IN HABROBRACON, SCIARA AND 



LYMANTRIA DISPAR 3° 



5. GENETIC INTERSEXUALITY IN DROSOPHILA, CER- 



TAIN LEPIDOPTERA AND BIRDS 42 



6. SEX-DETERMINATION IN FISH AND THE LOWER ALGAE. 



SEX IN PARAMECIUM AND FUNGI. SEX-DETERMINA- 

 TION IN BRYOPHYTES. SEX IN THE HIGHER PLANTS 46 



7. SPECULATIONS CONCERNING THE EVOLUTION OF THE 



SEX-DETERMINING MECHANISM 5 1 



BIBLIOGIL\PHY 55 



GLOSSARY 



62 



AUTHOR INDEX 65 



SUBJECT INDEX 67 



72336 



Vll 



