CHAPTER X

The Origin of the Different Kinds 340 of Adaptations

– Form and Symmetry 340

– Mutual Adaptation of Colonial 350 Forms

– Degeneration 352

– Protective Coloration 357

– Sexual Dimorphism and Trimorphism 360

– Length of Life as an Adaptation 370

– Organs of Extreme Perfection 371

– Secondary Sexual Organs as 372 Adaptations

– Individual Adjustments as 375 Adaptations

– Color Changes as Individual 375 Adaptations

– Increase of Organs through Use 376 and Decrease through Disuse

– Reactions of the Organism to 377 Poisons, etc.

– Regeneration 379