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ILLINOIS STATE ACADEMY OF SCIENCE 



fluences will, on the other hand, be determined by factors 

 of an origin and significance different from tho&e con- 

 trolling only the dissemination of the seeds. 



In the first years of the barberry survey, it was sup- 

 posed that the most favorable locality for the develop- 

 ment of wild plantings was in regions characterized by 

 calcareous soils. This opinion seemed supported, in our 



Map 6. Cook County. Scale 2/16" = 1 mile. Markings same as Map 2. 



