THE DOGWOOD AND GUM 



245 



tion of the western mountain ranges which cut off the moisture 

 bearing winds from the Pacific. 



Gum stones are ahnost as common in the brown coals of central 

 Europe as in the Brandon lignites of an earlier day and the Oligo- 

 cene records are principally those of southern England and Germany, 

 showing for how many thousands of years the gums have been 

 accustomed to a swampy habitat. 



Fig. 44. Sketch IMap Showing Present Distribution (enclosed areas) 

 AND Fossil Occurrences of the Tupelo 



The gums appear to wane in the later Tertiary, if their geological 

 record as it is now kno^\Tl may be taken as a safe guide. Thus 

 there are but 4 or 5 Miocene species. On the other hand these 

 are widely distributed. An American Miocene form, again based 

 on the fruit stones, is found in the coastal deposits of diatomaceous 

 sediments in Virginia. In Europe the Miocene records include 

 various localities in Germany and in the components of the now 



