IX. THE CONTINUOUS PROCESS OF ADJUST- 

 MENT BETWEEN THE ENVIRONMENT 

 AND THE ANIMAL, WITH SPECIAL 

 REFERENCE TO OTHER ORGANISMS 



THE DYNAMIC OR PROCESS RELATION OF ANIMAL ASSOCIA- 

 TIONS AND AGGREGATIONS 



1. The Struggle for Existence. 



2. The Dynamic Relations of Aggregations and Associations, 



with Special Reference to Animal Associations. 

 a. The Relation of Animals to Pollination and to Plant 



Galls. 



6. Subterranean and Cave Associations. 

 c. Selected References on Aggregations and Associations. 



"Nothing is easier than to admit in words the truth of the 

 universal struggle for life, or more difficult at least I have 

 found it so than constantly to bear this conclusion in mind. 

 Yet unless it be thoroughly engrained in the mind, the whole 

 economy of nature, with every fact on distribution, rarity, abun- 

 dance, extinction, and variation, will be dimly seen or quite 

 misunderstood." DARWIN. 



"Every reflective biologist must know that no living being is 

 self-sufficient, or would be what it is, or be at all, if it were not 

 part of the natural world, although no truth is easier to lose sight 

 of. Living things are real things, . . . but their reality is in 

 their interrelations with the rest of nature, and not in them- 

 selves." W. K. BROOKS. (1906.) 



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