CONTENTS 



PAGE 



Preface ......... ix 



List of Illustrations. ...... xiv 



CHAPTER I 

 CONSTANT DIFFERENTIAL GROWTH-RATIOS 



§ i. Introductory ........ i 



§ 2. Constant Differential Growth-Ratios ... 4 



§ 3. Examples of Constant Differential Growth-Ratios. 13 



§ 4. Inconstancy of Form and Constancy of Form-change 38 



CHAPTER II 



THE COEFFICIENT OF CONSTANT GROWTH- 

 PARTITION ; AND SOME SPECIAL CASES 



§ 1. The Heterogony of Deer Antlers .... 42 



§ 2. The Coefficient of Constant Growth-partition . 49 



§ 3. Heterogony in Holometabolous Insects 55 

 § 4. Heterogony and Polymorphism in Neuter Social 



Insects ......... 61 



§ 5. Heterogony, Moulting, and Dimorphism ... 68 



CHAPTER III 

 GROWTH-CENTRES AND GROWTH-GRADIENTS 



§1 



§2 



§3 



§4 

 §5 

 §6 



§7 

 §8 



Growth-gradients within Single Organs ... 79 

 Steepness of Growth-gradient within an Organ and 



Growth-intensity of the Organ as a whole . . 83 

 Reversal of the Sign of the Growth-gradient in 



Negative Heterogony ...... 87 



The Form of Growth-gradients. . . . .90 



Growth-gradients in Regions of the Body . . 92 

 Graded Growth-intensity in the Different Planes 



of Space ......... 95 



Gradients in Growth-rate of Epidermal Structures 100 



Conclusion ......... 102 



xi 



