Contents. XV 



PART III. 



NUTRITION AND SELECTION. 



' PAGE 



I. Simultaneous Influence of Nutrition and Selection 



ON Various Characters 515 



1. Variability as a Nutritional Phenomenon 515 



Sensitive Period, 521 ; Nutrition of the Mother- Plant, 

 522 ; Selection and Nutrition, 523. 



2. Methods of Investigation 523 



11, The Length of the Fruit of Oenothera Lamarckiana. . . 528 



3. Correlation Between Individual Strength and Length 



of Fruit 528 



4. The Simultaneous Operation of Nutrition and Selec- 



tion 536 



Long-fruited Race, 544; Short-fruited Race, 546. 



5. Shifting of the Curves of Variability by Nutrition..., 551 



III, Curves of Ray Florets of the Compositae and of the 



Rays of Umbels in the Umbelliferae 556 



6. Obliteration of the Effect of Selection by Nutrition. . . 556 



Anethum, 559. 



7. Equilibrium Between the Effects of Selection and Nu- 



trition 562 



Chrysanthemum, 563; Coreopsis, 566; Bidcns, 567. 



8. Obliteration of the Effects of Nutrition by Selection. . . 569 



Coriandnim, 569; Madia, 571. 



9. Summary 573 



Index 577 



