46 



Kuriles. The genera with more than one endemic species are 

 Athyrium (2), Tofieldia (2),Salix (2), Cerastium (2), Aconitum (5), 

 Thalictrum (4), Cardamine {2) , Saxifraga (^) , Spiraea (2), Astraga- 

 lus (2, one only in S. Kuriles), Oxytropis (2), Hypericum (2), 

 Viola (3), Epilobium (t,), Primula (2), Gentiane {'i) , AdenopJiora 

 (2), Cirsium (5), Saussurea (5). The only one of these we fail to 

 get in America is the Campanulaceous Adenophora, which has its 

 center of distribution in Siberia. Of the 1629 species, no less than 

 1298, or 79.68%, also occur in Honshu, the main island of Japan. 

 Considering the proximity of Sakhalin Island, and its approach to 

 the Siberia mainland , it is surprising to learn that only 38 .37% of the 

 plants also occur on Sakhalin, and 43.65% on the mainland in the 

 Amur, Ussuri and Manchurian area. This is especially striking 

 when we find that 26.70% of the species are common to North 

 America. In this class of statistics, however, there lies a fallacy 

 which is liable to mislead. Thus, for instance, 18.83% of the 

 Yezo species are common to Kamtschatka, 17.86% to the 

 Northern Kuriles. Are we then to say that the flora shows more 

 affinity with that of North America than that of Kamtschatka? 

 The fallacy lies in the fact that the comparatively small northern 

 peninsula has a poor flora, whereas America has a large and 

 varied one, in which many diverse plants find a place. Thus, 

 again, it is stated that 45.24% of the Yezo plants live in Korea 

 a larger number than in the mainland opposite Yezo. Does 

 Yezo, then, have a more southern type of flora than the mainland? 

 Perhaps so, but Korea has a richer flora, and is better known 

 to the Japanese, and hence it might be expected that more 

 species would be found in common. The flora of Yezo certainly 

 strikes one as typically boreal. 



Comparing Yezo with the opposite Siberian mainland, certain 

 facts are especially noteworthy. Out of 70 species of ferns in 

 Yezo, it appears that only 32 grow in the Manchuria-Amur, 

 Ussuri region. Ferns are excessively abundant on Honshu, as 

 I myself observed, and they so indicate relatively warm and 

 moist conditions. Yezo has 14 species of conifers {Abies mayriana 

 is endemic) of which only four are listed from the adjacent 

 mainland. I have, however, a list of nine species from the 

 maritime province of Siberia. Professor A. Henry has written 

 calling my attention to the remarkable endemism exhibited 

 by some of the East Asiatic trees, referring especially to the 



