XIV 



List of Illustrations 



FIGURE 



15. Diagram of F2 showing ratio 9:3:4 



16. Diagram of F2 showing ratio 9:7. 



17. Diagram of Fg in Sweet Pea' showing ratio 27 : 9 : 28 



18. Pedigrees of eye-colour in Man .... 



19. Pollen grains of Sweet Peas 



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



21. Heredity of a peculiar form of curly hair 



22. Descent of congenital lock of white hair . 



23.- Brachydactylous hands ...... 



24. Skiagram of hands . . . . . 



25. Hands of brachydactylous child , . . . 



26. Pedigree of brachydactylous family .... 



27. Descent from brachydactylous members 



28. Drinkwater's pedigree of brachydactyly 



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



30. Another cataractous family ..... 



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



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



33. Ideal Scheme of descent of simple sex-limited condition 



e.g. horns of Sheep ...... 



34. Tentative representation of descent of Colour-blindness 



35. Polish X Rivet Wheat 



36. Seeds of Polish x Pivet Wheat 



37. Reversion in height of Sweet Peas .... 

 2i2>. Two types of dwarf Sweet Peas .... 



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