THE QUADRAT METHOD IN TEACHING ECOLOGY 



281 



The relation between number and size of plants is shown in the 

 table. 



These results are very similar to those preceding. 



In the spring of 1918 the struggle among 7,350, 7,100, and 

 10,350 individuals per square meter respectively was terminated 

 by the area being converted into a garden. However, in the 

 fall an examination was made to see if the same principle apphed 

 as regards competition and reduced size to a family of Iva 

 xanthiifolia. The results are shown in the following table. 



Investigations in other areas will undoubtedly reveal similar 

 relations. 



Such studies, so elementary that a class can secure sufficient 

 data for conclusions in a single afternoon, point the way to an 

 investigation and discussion of some of the most fundamental 

 questions of ecology. It involves the problems of aggregation, 

 seed production, size and genninability of seeds, analysis of 

 competition, causes of dominance, reactions, etc. Moreover it 

 throws much light upon many problems in crop ecology (cf. 11). 

 Among these are method and the rate of seeding, i.e., thick or 

 thin stand, uneven germination, and its effect upon yield, com- 

 petition, effects of weeds upon cultivated crops and upon sum- 



