NEW PLUMS AND PRUNES 147 



with the nucleus of the plant ovule there are 

 various characteristic dividings and interlinkings 

 between the two sets of chromosomes within the 

 two nuclei. 



In the blending and rearrangement of these 

 minute structures, he believes that he is witness- 

 ing the underlying processes that bespeak the 

 blending of hereditary potentialities and their 

 recombination to determine the future possibil- 

 ities of the new organism that is thus brought 

 into being. 



All this is very wonderful. But it brings us 

 after all only one stage nearer the confines of 

 the mystery. The chromosomes within the nu- 

 cleus, which all biologists nowadays regard as 

 the tangible carriers of hereditary tendencies or 

 capacities, are few in number, and, small as they 

 are, we are forced to conclude that each of them 

 must be the carrier, not of a single potential trait 

 or tendency, but of a multitude of such potential 

 traits or tendencies. 



Our practical experiments in plant breeding 

 have shown us that we deal often with a dozen 

 or more tangible characters that are grouped 

 against each other in opposing pairs definitive 

 qualities of size or color or flavor of fruit and 

 all the rest and it requires but a moment's 

 thought to see that each of these "unit charac- 



