On the Generation of Animals

 Table of Contents

 Book I

 1

 2

 3

 4

 5

 6

 7

 8

 9

 10

 11

 12

 13

 14

 15

 16

 17

 18

 19

 20

 21

 22

 23

 Book II

 1

 2

 3

 4

 5

 6

 7

 8

 Book III

 1

 2

 3

 4

 5

 6

 7

 8

 9

 10

 11

 Book IV

 1

 2

 3

 4

 5

 6

 7

 8

 9

 10

 Book V

 1

 2

 3

 4

 5

 6

 7

 8

9

The natural birth of all animals is head-foremost, because the parts above the umbilical cord are larger than those below. The body then, being suspended from the cord as in a balance, inclines towards the heavy end, and the larger parts are the heavier.