LUTHER BURBANK 



each individual chromosome of the group lying 

 within the nuclei of pollen grain and ovule since 

 these are by no means at the limits of visibility. 

 And each atom has itself specific individuality. 

 Each group of a thousand atoms or so might make 

 up a molecule of a different type of protoplasm. 



So here is material for millions of kinds of 

 protoplasm, were so many needed. 



Here within the infinitesimal germ cell, re- 

 vealed to us in part by the microscope of the biolo- 

 gist and for the rest made manifest in imagination 

 by the revelations of the physicist, is material 

 enough to supply tangible carriers for all the con- 

 ceivable hereditary factors that come to make up 

 the most complex organism of any plant, or for 

 that matter of any animate creature whatever. 

 THE GERM CELL A COMPLEX ORGANISM 



Let us make the illustration specific. Suppose 

 that the chromosome in the nucleus of any given 

 pollen grain say that of a plum blossom were 

 of the very smallest size visible under the micro- 

 scope. Suppose, also, merely for the sake of illus- 

 tration, that the hereditary factors for unit char- 

 acters that it bears are of a thousand different 

 types representing all details of size and color 

 and foliage and growth and leaf and blossom and 

 fruit of the future tree. We know that the 

 chromosome really does bear these potentialities; 



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