CHAPTER X. 



LAWS OF ADAPTATION. 



Laws of Indirect or Potential Adaptation, — Individual Adaptation. — 

 Monstrous or Sudden Adaptation. — Sexual Adaptation. — Laws of Direct 

 or Actual Adaptation. — Universal Adaptation. — Cumulative Adaptation. 

 — Cumulative Influence of External Conditions of Existence and 

 Cumulative Counter-Influence of the Organism. — Free Will. — Use and 

 Non-use of Organs. — Practice and Habit. — Correlative Adaptation. — 

 Correlation of Development. — Correlation of Organs. — Explanation of 

 Indirect or Potential Adaptation by the Correlation of the Sexual 

 Organs and of the other parts of the Body. — Divergent Adaptation. — 

 Unlimited or Infinite Adaptation. 



In the last chapter we reduced into two groups the phe- 

 nomena of Adaptation or Variation, which, in connection 

 and interaction with the phenomena of Heredity, produce 

 all the endless variety of forms in animals and plants — 

 first, the group of indirect or potential, and secondly, the 

 group of direct or actual Adaptation. We shall occupy 

 ourselves with a closer examination of the different laws 

 which we can discover in these two groups of the phe- 

 nomena of variation. Let us first take into consideration 

 the remarkable and very important, although hitherto 

 much neglected, phenomena of indirect variation. 



Indirect or potential adaptation manifests itself, it will be 

 remembered, in the striking and exceedingly important fact 



