Fig. 5.5. Reversion to full inleusity of pigmentation on crossing a pink-eyed cream-and-white rat with 

 an albino. P, parents; cream-and-white at left, albino at right. Fi, one of the black-and-white young. 

 F2, cream-and-white at left, black-and-white in middle, albino at right. Their numerical relations are 

 about as .1 :9 :4. A slight departure from these proportions is observed on account of linkage (in this 

 case repulsion) between the genes for pink-eye and albinism. See chapter on Linkage. 



