CONTENTS. 



PART I. 



THE ORIGIN OF HORTICULTURAL VARIF/FIES. 



PAGE 



I. The Significance of Horticultural Varieties in the 



Theory of Selection* 3 



1. Variability in Garden Plants 3 



2. The Doctrine of the Increase in Variability in One 



Direction Brought About by Selection 9 



II. Latent and Semi-latent Characters i8 



3. Evcrsporting Varieties 18 



4. Half Races and Half Curves 26 



5. Trifoliuni Pratense Quinqucfoliuni. An Evcrsporting 



Race 36 



III. The different Modes of Origin of New Species 56 



6. Horticultural and Systematic Varieties and Elementary 



Species 56 



7. Progressive, Retrogressive and Degressive Formation 



of Species 65 



IV. The Sudden Appearance and the Constancy of new 



Varieties 76 



8. Examples of Constant Races 76 



9. Sterile Varieties 8S 



10. Instances of Races which Have Arisen Suddenly in 



Nature 95 



11. Horticultural Varieties which Have Arisen Suddenly. 99 



V. Atavism 104 



12. Atavism by Seeds and Buds 104 



13. Vilmorin's Suggestion as to the Origin of Striped 



Flowers 113 



14. Antirrhinum Majus Striatum 120 



■ L 



^v 





