19I4-] SOUTHEASTERN NORTH AMERICA. 157 



The fossil records will have to be much more complete before the 

 original center of radiation of the Moraceae can be determined, the 

 present brief sketch can be said to merely indicate that not only Fiats, 

 but other genera like Artocarpus that are entirely oriental in the pres- 

 ent, were normal elements in North America floras, from the time 

 of the modernization of these floras at the beginning of the Upper 

 Cretaceous onward. Along our east coast, they apparently became 

 restricted in their range at the dawn of the Miocene and they ap- 

 parently never after became as important in southeastern North 

 America as they had been, or as they are in the recent flora of the 

 Orient. 



The order Proteales includes the single family Proteaceae with 

 about one thousand existing species. They include the prominent 

 arborescent forms of Choripetalas in the Southern Hemisphere, to 

 which region all but the four genera Roupala, Protea, Leucospermum 

 and Helicia are confined. They are usually considered as Australian 

 types, in fact the majority of the genera and species are confined to 

 that continent, nevertheless there are four genera in South America 

 together containing over fifty existing species, and there are several 

 genera peculiar to the African flora; and the genus Helicia is predom- 

 inantly Asiatic. 



The geologic history of the Proteaceae is perhaps one of the most 

 striking instances that paleobotany affords of the great difference in 

 geographical distribution in former ages from what could possibly be 

 inferred from a study of the present geographical distribution of the 

 members of this family, although there are some significant features 

 in the distribution of the recent forms that will be alluded to in a 

 subsequent paragraph. 



The discovery of fossil forms of Proteaceae in the Tertiary depos- 

 its of Europe was the inspiration of a considerable literature 17 and 

 was the occasion of a rather acrimonious controversy regarding their 

 botanical affinity. This is well illustrated in the dissenting opinions 

 expressed by the botanists Hooker and Bentham who both regarded 

 fossil leaves as undeterminable. Starting with this apriori principle 

 it is difficult to see how they could arrive at any other conclusion. 



17 See the writings of Unger, Heer, Ettingshausen, Schimper, Schenk and 

 Saporta. 



