CONTENTS. 
PART I. 
THE ORIGIN OF HORTICULTURAL VARIETIES. 
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 18 
3. Eversporting Varieties 18 
4. Half Races and Half Curves 26 
5. Trifolinm Pratense Quinquefolium, An Eversporting 
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 88 
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 Striatnm 120 
