xiv List of Illustrations 



FIGURE PAGE 



15. Diagram of F 2 showing ratio 9:3:4 . . . 77 



1 6. Diagram of F 2 showing ratio 9:7. . . . . 89 



17. Diagram of F 2 in Sweet Pea showing ratio 27:9:28 . 91 



1 8. Pedigrees of eye-colour in Man ... .108 



19. Pollen grains of Sweet Peas . . .150 



20. Heredity of horns in Sheep . . . . . . 171 



21. Heredity of a peculiar form of curly hair . .207 



22. Descent of congenital lock of white hair .... 207 



23. Brachydactylous hands ..... 211 



24. Skiagram of hands . ... 212 



25. Hands of brachydactylous child . 213 



26. Pedigree of brachydactylous family ... .214 



27. Descent from brachydactylous members . . . 214 



28. Drinkwater's pedigree of brachydactyly . . 215 



29. Descent of prae- senile cataract . . . . . 216 



30. Another cataractous family . . . . . 217 



31. Descent of stationary night-blindness . between pp. 220-221 



32. Descent of Colour-blindness . . . . . 223 



33. Ideal Scheme of descent of Colour-blindness . . 225 



