EAR-SIZE 



29 



heterogeneity among the gametes of either parent, although both were 

 cross-bred individuals. 



Females 175 and 178 (cross 3) were also used in back-crosses with a 

 lop-eared male (179), resulting in the production of three-quarter-blood 

 lops. The character of these young is shown in table 18. 



TABLE 18. 



The data for mating i are incomplete; but those recorded for mating 2 

 are entirely satisfactory. They show a total range of variation in ear- 

 length at 26 weeks of 15 mm. which is very similar to that found in cross 

 3, by which the mother was produced. The greatest minus deviation 

 from the mid-parental ear-length is 5 mm.; the greatest plus deviation, 

 10 mm.; the average deviation, 4.6 mm. The nearest approximation to 

 the short-eared parent is 15 mm., to the long-eared parent 10 mm. The 

 inheritance may fairly be described as blending, with no evidence of seg- 

 regation in F 2 . 



The half-blood lop J 176 was also employed in a back-cross with his 

 mother, the Belgian hare, 431 (plate 3, fig. 9). Table 19 shows the 

 result obtained. 



TABLE 19. 



