232 LUTHER BURBANK 



length the theories of heredity. For the moment 

 it is enough to reflect that as the offspring in 

 each successive generation spring from the 

 parent, the germ plasm may be thought of as 

 a continuous stream uniting the remotest ances- 

 tor of any given strain with the most recent 

 descendant. 



Every tree in the orchard, for example, car- 

 ries within its tissues a portion of protoplasmic 

 chemical matter that has come down to it through 

 an almost infinite series of growths and divi- 

 sions in unbroken succession from the first tree 

 that ever developed on the earth or, for 

 that matter, from a vast series of more primitive 

 organisms that were the progenitors of the 

 first tree. 



And while this stream of primordial proto- 

 plasm has been changed by an infinitesimal 

 quantity in each successive era, it has retained 

 even to the present the fundamental character- 

 istics that it had from the outset. 



That such is the case seems little less than a 

 miracle; that an almost microscopical speck of 

 protoplasm which we term a pollen grain should 

 contain the potentialities of thousands of genera- 

 tions of ancestors, and should be able to transmit 

 them with such force that the seed growing from 

 the ovule fertilized by that pollen grain will 



