450 A PINE AND ARCTIC PLANTS 



are dyked in from the sea, they soon become covered with 

 grasses and carices, the seeds of which are supposed to be 

 washed down by streams and mingled with the marine silt ; 

 and fragments of grasses abound in the Post-tertiary clays of 

 the Ottawa. 



It seems almost ridiculous thus to connect the persistence of 

 the form of a little plant with the subsidence and elevation of 

 whole continents, and the lapse of enormous periods of time. 

 Yet the Power which preserves unchanged from generation to 

 generation the humblest animal or plant, is the same with that 

 which causes the permanence of the great laws of physical 

 nature, and the continued revolutions of the earth and all its 

 companion spheres. A little leaf, entombed ages on ages ago 

 in the Pleistocene clays of Canada, preserves in all its minutest 

 features the precise type of that of the same species as it now 

 lives, after all the prodigious geological changes that have 

 intervened. An Arctic and Alpine plant that has survived all 

 these changes maintains, in its now isolated and far removed 

 stations, all its specific characters unchanged. The flora of a 

 mountain top is precisely what it must have been when it was 

 an island in the glacial seas. These facts relate not to hard 

 crystalline rocks that remain unaltered from age to age, but to 

 little delicate organisms that have many thousands of times 

 died and been renewed in the lapse of time. They show us 

 that what we call a species represents a decision of the un- 

 changing creative will, and that the group of qualities which 

 constitutes our idea of the species goes on from generation to 

 generation animating new organisms constructed out of differ- 

 ent particles of matter. The individual dies, but the species 

 lives, and will live until the Power that has decreed its creation 

 shall have decreed its extinction ; or until, in the slow process 

 of physical change depending on another section of His laws, 

 it shall have been excluded from the possibility of existence 

 anywhere on the surface of the earth, unless we suppose with 



