Interaction 



An interrelationship between organisms, between organ- 

 isms and the environment, or between environmental factors, 

 e.g., Competition, grazing, wilting of a plant, Relative 

 humidity decreased by heat. See Coaction, Reaction. 



Intercellular 



Refers to the position between cells of an organism, e.g., 

 air-spaces between cells in leaves. 



Interception 



The process by which precipitation is retained by leaves, 

 branches, and other organs of plants before the moisture 

 reaches the ground. 



Interference 



The ability of a species to damage another either directly 

 by attacking its individuals or indirectly by harming its 

 resources or blocking access to them. cf. Competition, 

 Exploitation. 



Interfluve 



A ridge between river valleys. 



Internal Drainage (Soil) 



The quality of a soil that permits downward flow of 

 excess water through it, determined by the texture, structure, 

 depth to the Water table, etc. cf. Gravitational water. 



Internal Environment 



The conditions within an organism or cell that influence 

 its processes, e.g., the oxygen content in body fluids in ani- 

 mals or in air-spaces in plants. 



Interspecific 



Refers to relations or conditions between species, cf. 

 Intraspecific. 



Interspecific Association 



See Association, interspecific. 



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