EVAPORATION AT SKOKIE MARSH 



155 



The stretches of forest present in many places at the edge of 

 the marsh, while not usually considered as belonging to the marsh, 

 are of interest because of the light that they throw upon the suc- 

 cessional development of vegetation with the passing away of 



Fig. 1. Map of Skokie Marsh; the dotted line represents Skokie Stream 



marsh conditions. Along the east side of the marsh, the ground 

 surface slopes gently upward toward a rather high morainic ridge 

 that roughly parallels the marsh. And as one proceeds toward 

 this ridge, he leaves behind him such woody species as Cornus 



