EAR-SIZE 



31 



mm. respectively the mid-parental ear-length. Litter 2, on the other hand, 

 was born in the winter. It consisted originally of 8 individuals. The 

 2 weakest ones in the litter died, one previous to, the other subsequent 

 to weaning. The 4 largest ones were stolen, leaving 2 survivors, <? 754 

 and <^755, both of which when last measured gave evidence of having 

 been permanently stunted in size and ear-length by the hard conditions 

 under which they had developed. They are too abnormal to throw any 

 light on the inheritance of ear-length in this cross. 



MATENGS OF THREE-QUARTER-BLOOD LOPS. 



The male 319, employed in the matings last described, was also used 

 in crosses with short-eared rabbits and with a three-quarter-blood lop, 

 his sister. The results of the crosses with short-eared females are shown 

 in table 21. 



TABLE 21. 



The 7 young produced by mating i fluctuate about the mid-parental 

 condition of ear-length. The greatest minus variation is n mm., the 

 greatest plus variation 8 mm., giving a total range of variation of 19 mm. 

 This is not large, considering that the difference between the parents is 

 95 mm. The greatest deviation from the mid-parental, n mm., is 36 

 mm. removed from the nearest parental ear-length, that is, it is less than 

 one-third as great as the least deviation from either parent. The inheri- 

 tance is unmistakably blending. Even more clearly is this the case in 

 mating 2. The parents differ in ear-length by 100 mm. The young are 

 all almost exactly intermediate. The entire range of variation in the 6 

 young is only 5 mm., while the nearest approximation to the ear-length 

 of either parent is nine times this amount. A better example of fully 

 blending inheritance can scarcely be imagined. In neither mating do 

 we get evidence of heterogeneity among the gametes formed by the three- 

 quarter-blood father (319). 



