xiv LIST OF ILLUSTRATIONS 



FIGURES PAGE 



6. The beginning of a fruit-spur system in the apple 27 



7. A flower-cluster base that has produced a fruit-bud and a long 



shoot. (Rome apple) 28 



8. Branched fruit-spur system of the apple 28 



9. Axillary fruit-bud formation in the pear 29 



10. A vigorous fruit-spur of the pear 30 



1 1 . Fruiting habit of the peach 30 



12. Fruiting habit of the sour cherry. A strongly vegetative type 32 



13. Floral diagram of the apple. (After E. J. Kraus, Ore. Agr. 



Exp. Sta. Research Bull. 1, part 1) 35 



14. Early stages of fruit-bud differentiation in the apple. (After 



E. J. Kraus, Ore. Agr. Exp. Sta. Research Bull. 1, part 1). . 36 



15. Diagram indicating positions of four flower primordia 37 



16. Diagrammatic representation of origin of calyx primordia on 



edge of torus 37 



17. Diagram showing development of the apple. (After E. J. 



Kraus, Ore. Agr. Exp. Sta. Bull. 1, part 1) 42 



18. Diagrammatic drawing of an apple inflorescence or peduncle 



from which arise the pedicelled flowers. (After C. A. Black, 



N. H. Agr. Exp. Sta. Tech. Bull. 10) 43 



19. Showing parts of a flowering branch 43 



20. A, medium lengthwise section of a mature apple; B, cross-sec- 



tion of same. (From Robbins, Botany of Crop Plants, by 

 permission of P. Blakiston's Sons Co.) 46 



21. Diagram illustrating distribution of bundles in the torus and 



pedicel apex. (After E. J. Kraus and G. S. Ralston. Ore. 

 Agr. Exp. Sta. Bull. 138) 47 



22. Diagram to illustrate the hypotheses involved in Classes I, II, 



III, and IV 56 



23. Diagrammatic representation of arrangement of scaffold limbs 



in pruning 76 



24. Showing the type of growth that commonly follows the cutting 



of the terminal : 89 



25. Showing a type of growth that follows when the terminal is not 



removed. The buds which give rise to shoots are usually not 

 confined to the terminal ones 90 



26. A graphic representation of the cycle of nitrogen through the 



plant and the soil. (After M. A. Bachtel, Ohio Agr. CgII. 

 Ext. Bull, Vol. 8, No. 1, 1912) 151 



