22 Viewpoint of Modern Ecology 



some situations or for some organisms and quite unmodifiable for 

 others. In the succeeding chapters the more general, often unmodi- 

 fiable, factors will be scrutinized first, and will be followed by a 

 discussion of the more commonly modifiable factors. This will lay 

 the foundation for a consideration in the later chapters of the com- 

 position and functioning of the community as a whole. 



