LIST OF ILLUSTRATIONS 



FIGURE Page 



1. An animal clock of the seasons in an Illinois Woodland.. 53 



2. Food- web relationships in the aspen parkland of 



Canada 63 



3. Monads 68 



4. Colpoda 68 



5. Hypotrich infusorians 69 



6. Paramecium 70 



7. Vorticella 72 



8. Amoeba 72 



9. Tribolium beetles in floury environment 86 



10. Rate of increase of population of Tribolium beetles 128 



11. Marine flatworm, Procerodes 130 



