ON TIMBER TREES 



the existing trees have passed and through which 

 the diversified hereditary factors were implanted 

 in their racial germ plasms. 



A knowledge of this story we owe to the geolog- 

 ical botanists. They have sought diligently in the 

 rocks for fossil remains, and by joint effort, search- 

 ing all around the world, have been able to repro- 

 duce a picture of the main story of the evolution 

 of existing forms of vegetable life. 



It is by recalling the story which they tell us, 

 and thus alone, that we are enabled somewhat 

 clearly to apprehend the possibilities of variation, 

 and through variation of so-called new develop- 

 ment consisting essentially of the re-combination 

 and intensification of old ancestral traits that we 

 have witnessed in the case of many tribes of plants 

 in the course of our experiments. 



A brief resume of this story of plant life in the 

 past, with particular reference to our own flora, 

 will serve in the present connection to explain why 

 there is every warrant for believing that each and 

 every one of our forest trees contains submerged in 

 its heredity the potentialities of a development of 

 which its exterior appearance gives but faint 

 suggestion. 



It appears that there is full warrant for the 

 belief that the modern flora originated in the 

 northern hemisphere, and probably in the region 



[181] 



