VIII - Principles of Sexual Selection Part 1

VIII - Principles of Sexual Selection Part 2

VIII - Principles of Sexual Selection Part 3

VIII - Principles of Sexual Selection Part 4

VIII - Principles of Sexual Selection Part 5

VIII - Principles of Sexual Selection Part 6

IX - Secondary Sexual Characters in the Lower Classes of the Animal Kingdom

X - Secondary Sexual Characters of Insects Part 1

X - Secondary Sexual Characters of Insects Part 2

10 - XI - Insects, continued

XII - Secondary Sexual Characters of Fishes, Amphibians, and Reptiles Part 1

XII - Secondary Sexual Characters of Fishes, Amphibians, and Reptiles Part 2

XIII - Secondary Sexual Characters of Birds Part 1

XIII - Secondary Sexual Characters of Birds Part 2

XIII - Secondary Sexual Characters of Birds Part 3

XIV - Birds - Continued Part 1

XIV - Birds - Continued Part 2

XIV - Birds - Continued Part 3

XV - Birds - Continued Part 1

XV - Birds - Continued Part 2