116 



PHYSICAL BASIS OF HEREDITY 



such groups as those given by Bateson. Even were it pos- 

 sible to suppose that in each case a different reduplica- 

 tion occurred {Le., a different number of generations was 

 passed through), still, as said above, it is not obvious 

 that the linkage series stands in any such numerical (i.e., 

 dichotomous) relation as the view demands. 



ABxab 



[ AB ab ] 



AbxaB 



( Ab.aB J 



n-i 



n-i 



3&B 



IBa 



MB 



Fio. 51. — Two schemes illustrating the idea of reduplication by Bateson and 

 Punnett; the three figures to the left illustrating "coupling," and the three to the right 

 "repulsion." 



2. If reduplication occurred at an early stage in the 

 germ tract, we should expect to find in any organ of limited 

 size, as a stamen, that there would be a likelihood that it 

 would contain for the most part a particular kind of ceU. 

 Altenburg tested out this view with pollen of the primrose 

 and found no evidence in favor of a limited distribution — 

 on the contrary, he found that all the linkage combinations 



