— 225 — 



Hence : the évidence of transport lietween Assam and China is vcry niuch 

 less than thaï of communication between Assam and Furiher-India. So tliat 

 there would be no more reason to coiisider Assam, than China to be the 

 native country of „the" tea-plant. Or again to put it otherwise: China has 

 a flora of its own, that is widely divergent from the Burmese (and Assamese) 



plant world. 



The same conclusion is to be found back in the comprehensive studies 

 of DiF.Ls, the well-known specialist for the flora of Western China. In 

 his summary of the flora of Yun-nan ') he points at the striking conformity 

 between the végétations of Sze-chuen and Yun-nan, whereas the frontiers 

 of the latter (particularly the neighbourhood of Sze-mao and of Ta-li-fu) 

 hâve a flora that differs from the Chinese végétation, and bears an unmis- 

 takable Further-indian stamp. Of course there exisis no sharp limit between 

 both floras, nevertheless they are noticeably divergent. Indirectly, this may 

 appear also from the interesting phenomenon, noted by Diels, that the 

 flora of Sze-chuen (and therefore also partiy that of Yun-nan) has much 

 more éléments in common with the western parts of the Himalaya, than 

 with the eastern tracts; whereby he feels driven to the hypothesis that 

 the flora of Western Sze-chuen has taken its way thither throngh Tibet, 

 not through Burma ^). Hence the eastern part of the Himalaya, i.e. close 

 by Assam, has remained pretty well free from Chinese éléments. Taking 

 ail points into account, we see many différences between Further-India 

 and Assam on the one hand. and China on the other; and though such a 

 gênerai stalistical comparison between whole floras of enormous areas has 

 very little conclusive value as évidence for the ancient migrations of one 

 single species, it should not be forgotten that it is the only argument 

 available to historical phytogeography. 



Exchange between Assam and China being improbable from a phyto- 

 geographical point of view, two possibilities remain: either the tea plant 

 and her allies were distributed from the Ante-Tibetan range East- and 

 Westward, or they hâve inde.pendently originated on both sides of those 

 mountains. Now, may we really feel justified in nssuming (of course with 

 ail possible reserve !), that ail tea, large- as well as small-leaved, has 

 corne from the Ante-Tibetan mountains 3)? Yes, and no. ~ Yes, inasmuch 

 as thèse mountains very probably contain a flora still quite unknown to 

 us"*), and besides hâve been more completely preserved in their original 



') L. Diels 1913, p. 60, 62, 68. 



2) L. Diels 1913, p. 80-85. 



3) As to the part that the valleys might hâve played in distribution from North to 

 South (a principle that has already been admitted by Mr. Me. Clellano according 

 to Griffith, 1838, p. 160), Diels (1913, p. 71) does not think that it has been an 

 important one, as thèse deep incisions hâve hardly any bankgrounds where plants 

 might get a firm footing. 



♦) ..Die Kenntnis ihrer offenbar ausserordentlich reichen Flora ist noch so diirftig, dass 

 .,es gewagt vvarc, darauf allgemeine Schiiisse zu griinden." (L. DiELS 1901, p. 170.) 

 ,,Hier liegt das Sammelbecken fiir aile Vegetationen Ost-Asiens; es ist ganz her- 

 „vorragend reich und ein in seiner Fernwirkung vielleicht unerreichtes Fioren-Gebiet 

 „der Erde." (Ibid., p. 650.) 



