ORGANIC ADAPTATION 



335 



ing cross-fertilization. And so the Bee which has been given as our 

 final example of adaptation to the physical environment, serves 

 also as an introduction to the consideration of adaptation to the 

 living environment. No better proof could be asked of the futility 

 of attempting to classify the adaptations of organisms — the 

 organism is a unit: a complex of adaptations to any and all of 

 its surroundings, inanimate and animate, otherwise it could not 

 exist. 



B. Adaptations to the Living Environment 



We now turn more specifically to some striking interrelations 

 of organism with organism, in order to make possible an apprecia- 

 tion of the devious means to which they have recourse — to what 



Fig. 220. — Diagram of the web of life and the equilibrium of nature, as 

 illustrated by the food relations in a pond community. Arrows point from the 

 organisms eaten to those doing the eating. The task of ecology is to decipher 

 the patterns of the web of life. (From Shelford.) 



extent the strands of the web of life become entangled — in the 

 competition for a livelihood. 



The mutual biological interdependence of organisms is, in the 

 final analysis, the result of the primary demands of all creatures — 

 proper food, habitat, reproduction, defense against enemies and 

 the forces of nature. The web of life is an expression of the coopera- 

 tion, jostling, and strife of individual with individual, and species 

 with species for these primary needs; and the activities which 

 follow from them form the foundations of life in the lowest as well 



