Plant Mi'^ration Studies 21 



MAPS SHOWING DISTRIBUTION OF NEBRASKA TREES 



(Compiled from specimens and available data in the Herbar- 

 ium of the Botanical Survey of Nebraska. The lines are drawn 

 so as to show the general distribution of each species, it being 

 impossible to show details on maps drawn to such a small scale. 

 In some cases isolated stations have been connected where there 

 is good reason for believing that the species extends from one 

 to the other, while in others no such attempt has been made, 

 although further investigation will probably show intermediate 

 stations, if not an actual continuity.) 



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