COAT CHARACTERS IN GUINEA-PIGS AND RABBITS. 



A result of this sort can have followed either from matings inter se 

 of animals of class (2), page 48, or from matings of such animals with 

 those of class (i). In either case the young should be 353 Pdto i Pp, 

 a ratio closely approximated in the observed 23 P d to 7 Pp. 



III. The following pairs gave only dark-eyed and albino young, 

 without pink-eyed pigmented ones : 



Such a result would be produced either by mating inter se individ- 

 uals of class (3), page 48, or by mating individuals of that class with 

 those of class (i). In either case the young should be as 3 Pdto i A. 

 The observed numbers, 2410 6, are not greatly at variance with this ratio, 

 considering the small number of young produced. 



IV. The following pairs produced only dark-eyed pigmented young, 

 without either albinos or pink-eyed pigmented young ; 



Such a result should follow mating inter se two individuals of class 

 (4), page 48, or mating an individual of that class with one from any 

 of the other three classes, (i) to (3), or from a mating between classes 

 (2) and (3). 



Accordingly, in the eighteen pairs which Darbishire formed of dark- 

 eyed pigmented mice of this second filial generation (omitting only 

 one pair which gave but a single young), we get evidence of the 

 probable existence of all four of the hypothetical classes of dark-eyed 

 individuals. If the pairs were taken quite at random without regard 

 to the recessive characters present in the different animals (and this 

 was evidently the case, since Darbishire does not admit the existence 



