;;il IMIKHITANCK IX GUINEA-PIGS. 



Th) e capable theoretically of forming 16 diflferent combinations, 

 ollows, heterozygous combinations being omitted. The appearance 

 ontaining each of these several combinations is indicated 

 () pj, pective combinations. 



AlK'K. golden agouti = wild type. 

 Single mutations. 



\!U •,.. blade-eyed red. AbCF:, cinnamon. 



silver agouti. aBCE, black. 



Double mutations. 



AIH' r r. red-eyed white. 



AbCrE, silver cinnamon. 

 !'.. chocolate. 



AbCe, brown-eyed red. 

 aBC r E, red-eyed sepia. 

 aBCe, black-eyed red 



Triple mutations. 



AbCVe, redn yed white, 

 red-eyed white. 



abCe, brown-eyed red. 

 abCrE, red-eyed chocolate. 



Quadruple mutation. 

 abC r e, red-eyed white. 



• he I6different combinations, 2 produce black-eyedred individuals 

 indistinguishable except by breeding test; the same is true regarding 

 1 .r< iwn-eyed reds. Four other combinations identical with these, except 

 for the substitution of C r for C, produce red-eyed whites, which visibly 

 all alike but which breed differently. Three of the four kinds of 

 red-eyed whites have been identified by breeding test; no doubt the 

 fourth can easily be obtained. The fact that the several classes of 

 red-eyed whites look alike, and that the two kinds of black-eyed reds 

 look alike, and further, that the two kinds of brown-eyed reds look 

 alike, reduces the number of visibly distinguishable classes from 16 to 

 1 1 , all excepl one of which have been recorded from this single experi- 

 ment. The experiment also produced albinos which theoretically 

 Bhould 1" different formula), if in the formula C a is everywhere 



substituted for its allelomorphs C or C r . No attempt has been made 

 to distinguish the several expected classes of albinos by breeding tests, 

 the only certain means of identifying them. 



Hie cl menl observed between theoretical and recorded 



cumbers of V ■ offspring in this cross lends no support to the idea that 

 ciation or linkage occurs among the 4 factorial variations 

 involv 



