62 



COAT CHARACTERS IN GUINEA-PIGS AND RABBITS. 



Matings of these three sorts show the following results. The " ex- 

 pected " results are calculated on the hypothesis of persistent relative 

 potencies and full segregation of the rough and smooth characters. 



The agreement between the observed and the expected proportions 

 of fully rough (/?.) and partial-rough (PR.) offspring is sufficiently 

 close to lend support to the hypothesis of persistent gametic potency 

 from generation to generation. For on the alternative hypothesis, that 

 partial-rough hybrid animals form only partial-rough gametes and 

 smooth ones, no animals with the fully developed rough character 

 should be formed either in Group I or Group III of the foregoing 

 matings, but we see that young of this sort were produced in all these 

 groups. Yet it is probable that cross-breeding must be recognized as 

 an element which may modify the potencies of gametes, causing those 

 of a cross-bred individual to be less uniform in potency than those of 

 an animal not so crossed. Further experiments are needed to throw 

 light on this question. 



