CONTENTS 



PAGE 

 INTRODUCTION i 



PART I VARIATION 



CHAPTER 



I. VARIATION IN GENERAL 7 



I. Variation Universal among Living Beings .... 7 



II. Variability the Basis for Improvement 9 



III. Nature of Variability 10 



IV. Meaning of the Term " Character " 11 



V. Dominant and Latent Characters .13 



VI. The Unit of Variability . . 15 



VII. Distinctions as to Kinds of Variations . . . . . 17 

 References . . . . . . . . . .24 



II. MORPHOLOGICAL VARIATION . .25 



References 29 



III. SUBSTANTIVE VARIATION 30 



IV. MERISTIC VARIATION 33 



I. Symmetry 34 



II. Meristic Variation in Linear Series 39 



III. Meristic Variation and Bilateral Symmetry . . . -65 



IV. Symmetry in Variable Parts : . . . . . .68 



V. Meristic Variation in Radial Series 70 



VI. Importance of Meristic Variation . . . . . -73 

 References 74 



V. FUNCTIONAL VARIATION 75 



I. Variation in the Degree of Activity of Normal Functions be- 

 tween Different Individuals of the Same Species . . -77 

 II. Variation in the Degree of Activity of Normal Functions within 



the Same IndTvidual 91 



III. Modification of Normal Functions by External or Other Influ- 



ences . . . . . 98 



IV. Normal Functions exercised under Abnormal Conditions . .107 



References . : . . . . . . . . . 109 



VI. MUTATIONS . . . no 



I. Distinction between Mutation and Ordinary Variation . .no 



II. Examples of Mutation . in 



