42 E. B. BabcocJ{^ 



Canada and northwestern United States to the east, southeast, 

 and south. Furthermore, the existence of 14-chromosome species 

 in North America previous to the last or Wisconsin glacial 

 epoch, is proved by Fernald's discovery" of C. nana in an un- 

 glaciated island on the Gaspe Peninsula in eastern Canada. 

 Although no 8-chromosome species are know^n to occur in 

 Alaska, one such species (C. burejensis, which from its morphol- 

 ogy might have been an ancestor of the occidentalis group of 

 American species) is found in the Kurile Islands, and it might 

 easily have been distributed farther east at an earlier period. It 

 seems very probable, therefore, that these American species are 

 descendants of 8- and 14-chromosome species which migrated 

 into northeastern North America from Asia. 



Reviewing the evidence on distribution of these various groups 

 of related species in the subgenus Eucrepis, we find it consistently 

 pointing to south-central Asia as the region of common origin. 



In BarJ^hausia (fig. 11) the lo-chromosome species are cer- 

 tainly more primitive as a group than any of the 8-chromosome 

 species. They may be considered in two subgroups, namely, 

 those more or less resembling C. albida, and those clustering 

 around C. foetida. C. albida is a polymorphous sufFrutescent 

 perennial species of southwestern Europe and the Grand Atlas 

 Mountains in Morocco. C. alpina is a primitive type of annual 

 which is distributed from the Caucasus to western Asia Minor, 

 and C. syriaca is a closely related species occurring more to the 

 south. C. rubra is a less primitive congener of the southern Bal- 

 kans and Italy. It is worth noting, also, that there are two obvi- 

 ously related species in Abyssinia which have not yet been studied 

 cytologically. There is thus sufficient evidence of connection 

 between albida and the region of common origin for Eucrepis 

 and Catonia. The species in the foetida group are more closely 



