— 71 — 



p. that the development and distribution of Bupleuroflora in Eura- 

 sia are strictly connected to the activity of the Himalayan- Yunna- 

 nian secondary centre of evolution. 



From the last articles, §§ 5 — 7, we can clearly see, that Bu- 

 pleurum has no [secondary] centre in Japan and that its whole 

 Bupleuroflora is also straightly connected to the Himalayan centre. 

 This connection with the Extreme-East can be followed in t w о 

 ways: the first direct way goes in a direction more southern than 

 the plateau of Goby; the second way goes raund about the emi- 

 nences that surround this plateau from west and north, and ends 

 in the same region as the first one. By the first way came to Ja- 

 pan B. longiradiatum and — it is possible — B. nippon icum. 

 These species could make their way to Japan during the neogen, 

 because the catastrophe in the time of pleystocen barred the way 

 from the continent to Japan for the majority of land-organisms. 

 By the second way came to Japan B. triradiatum and, pro- 

 bably, B. f ale at urn scorzonerifolium. 



B. triradiatum migrated to North America, as it seems, not 

 later than the first half of the pleystocen. Hokkaido represents an 

 intermedial station between Kamtshatka, from where B. trira- 

 diatum migrated following the „arc of Kurile", and Sachalin, 

 where it could migrate by the „arc of Sachalin", which was probably 

 ■cut away by the sea [Thzuharu-Strait] -from its continuation in 

 Honshiu; it could not be afther the end of pliocen, but also not 

 -earlier than the middle of tertiär. 



§ 9, a statistical note. 



If we count the number of species certainly known from Japan 

 ^s equal to foui-, the genus will take the third or the fourth place 

 ^mong the Japanese Ammiaceae, Presl. by the number of 

 species. 



All the number of iVmmiaceae of Japan is probably and 

 approximately equal to с : a 100; if that is the case, В up leu- 

 rum make up 47o of all Japanese sciadophyts. It belongs to 

 a group of 17 genera, having one or some endemic species in 

 Japan. 



