FLIGHT OF PLANTS AND ANIMALS. 427 



do, with Europe and with our West, have their close counter- 

 parts in Japan and north China ; some in identical species 

 (especially among the herbs), often in strikingly similar ones, 

 not rarely as sole species of peculiar genera or in related ge- 

 neric types. I was a very young botanist when I began to notice 

 this, and I have from time to time made lists of such instances. 

 Evidences of this remarkable relationship have multiplied year 

 after year, until what was long a wonder has come to be so 

 common that I should now not be greatly surprised if a Sarra- 

 eenia or a Dioncea, or their like, should turn up in eastern 

 Asia. Very few such isolated types remain without counter- 

 parts. It is as if Nature, when she had enough species of a 

 genus to go round, dealt them fairly, one at least to each quar- 

 ter of our zone ; but when she had only two of some peculiar 

 kind gave one to us and the other to Japan, Manchuria, or the 

 Himalayas ; when she had only one, divided these between the 

 two partners on the opposite side of the table. As to number 

 of species generally, it can not be said that Europe and Pacific 

 North America are at all in arrears ; but, as to trees, either the 

 contrasted regions have been exceptionally favored or these 

 have been hardly dealt with. There is, as I have intimated, 

 some reason to adopt the latter alternative. 



We may take it for granted that the indigenous plants of 

 any country, particularly the trees, have been selected by cli- 

 mate. Whatever other influences or circumstances have been 

 brought to bear upon them, or the trees have brought to bear 

 on each other, no tree could hold its place as a member of any 

 forest or flora which is not adapted to endure even the extremes 

 of the climate of the region or station. But the character of 

 the climate will not explain the remarkable paucity of the 

 trees which compose the indigenous European forest. That is 

 proved by experiment, sufficiently prolonged in certain cases 

 to justify the inference. Probably there is no tree of the north- 

 ern temperate zone which will not flourish in some part of 

 Europe. Great Britain alone can grow double or treble the 

 number of trees that the Atlantic States can ; in all the latter 

 we can grow hardly one tree of the Pacific coast. England 

 supports all of them, and all our Atlantic trees also, and like- 

 wise the Japanese and north Siberian species, which do thrive 



