CH. XIV] PALAEOBOTANICAL STANDPOINT Ui 



species in the two regions. Survivals of this kind in Japan and 

 North America, Avhich are many, led to the recognition by Asa 

 Gray of the fact that the floras of Japan and Atlantic North 

 America are allied. 



(2) It may have occurred in two out of the three regions. Thus 

 Phellodendron, Actinidia, and Zelkowa have been exterminated 

 in Europe and probably in North America, but survive in the 

 East of Asia. Dulichium, Karzvinskia, Proserpinaca have been 

 destroyed in Europe and probably in East Asia, but survive in 

 North America. When such regional distribution has occurred, 

 there is nothing to indicate in the present how wide the distribu- 

 tion may have been in the past, or to say whether genera are 

 survivals or not. 



(3) Extermination may have extended to all three regions. In 

 that case the past is completely wiped out, and in the present 

 there is no sign of the life that has been. We have numerous 

 instances of such extermination in the case of species — extinct 

 species of Dulichium, Euryale, Liriodendron, and so on, far too 

 numerous to name here; but we have also in all probability 

 instances of genera exterminated in the many undetermined 

 fossil forms which would appear to belong to living families, but 

 cannot be placed in living genera. These forms are mostly un- 

 named so cannot be referred to, but by consulting the works 

 enumerated they will be recognised. 



It is this fact, that endemic species can frequently be proved 

 to be survivors from a wide-ranging past, which offered to me 

 the greatest stumbling-block to the acccj^tance of the theory of 

 Age and Area. So formidable did the difficulty appear that I 

 felt it must vitiate the reasoning which pointed to endemics as 

 the newest elements in plant-life; and yet it was hard to see 

 where the flaw could lie; and the theory offered so simple and 

 reasonable an explanation of much that one met with in palaeo- 

 botany. 



A student of Tertiary floras must stand by the fact that in 

 many instances endemics are survivors from races that once flour- 

 ished widely, though they do so no more. Take the genus Sequoia. 

 It once inhabited Europe, Eastern Asia, the Arctic regions, and 

 large areas of North America ; now it is confined to the Pacific 

 coast of California. Euryale, again, was once represented by 

 many species scattered at different times (some at the same 

 time) throughout Europe; now it survives as a single species 

 only in parts of Cliina and Assam. Or again, with individual 



