xxvi CONTENTS 



CHAPTER XXXVI 

 The Results op Evolution 



PAGB 



Adaptation 431 



Convergent Adaptations in Animals 431 



Convergent Adaptations among Plants 432 



Other Classes of Adaptations 433 



Food-Securing Adaptations 434 



Plants Adapted to Absorb Gases, Water, and Salts 435 



Insectivorous Plants 435 



Adaptations for Self- Defense 436 



Defense of Young 437 



Self- Defense in Plants 437 



Adaptations for Rivalry 437 



Rivalry among Plants 438 



Adjustment Adaptations in Animals 439 



Plant Adjustments 439 



Colors of Animals 440 



Protective Resemblance 441 



Colors of Physiological Value 442 



Warning Coloration 443 



Mimicry 444 



Flowers and Insects 446 



Section 11. The Distribution of Organisms 



CHAPTER XXXVII 

 Plant Distribution 



The Facts of Distribution 449 



The General Causes of Distribution 449 



Evolution and Distribution 450 



Migration and Distribution 450 



Adaptation and Distribution 451 



Floras and Faunas 451 



Vegetation 452 



The Barriers to Universal Distribution 453 



Tangible Barriers 453 



Intangible Barriers 454 



Biological Barriers 456 



The (Jrcat Plant Realms. 456 



The Holarctic Realm 457 



Vegetation of the United States and Canada 457 



Dcriduoua Forest 459 



Western Coniferous Forest 461 



Grasslands 463 



Desert 466 



Chaparral 468 



Swamps 470 



Summary 471 



