EAR-SIZE 



17 



Mating 2 (between brother and sister) produced 2 young, which reached 

 the age of 20 weeks. Though they were not large, their ears attained 

 a good length, the deviations from the mid-parental ear- length being 

 — 5 mm. and —2 mm. 



Table 2. 



1 Estimated. 



'Sick. 



Mating 3 (between mother and son) produced a litter of 5 young, which 

 grew in a satisfactory manner until 14 weeks old (see fig. 2). Then, 

 as a result of disease, 4 of them died, and the fifth became greatly reduced 

 in flesh, so that at 20 weeks of age he weighed 400 grams less than at 

 14 weeks of age. Nevertheless his ears continued to grow slowly. At 14 

 weeks they measured 220 mm.; at 20 weeks, 223 mm. 



The rabbit 671 was from the beginning much the smallest one in the 

 litter; we named him the "runt" and had hopes of securing from him a 

 race of small-sized but lop-eared rabbits. These hopes were ended by 

 the unfortunate illness which attacked the entire litter. The small size 

 of this rabbit accounts for the shortness of his ears (190 mm. at 14 weeks 

 of age). Leaving him out of consideration, the range of variation in ear- 

 length is 20 mm.; with him, it is 30 mm., at 14 weeks of age. 



Two of the young produced by mating 3 had already at 14 weeks of 

 age exceeded the mid-parental ear-length, a third had almost reached 

 it, while the 2 others fell below it. This is a fluctuating variation around 

 the mid-parental ear-length, and indicates that the long-cared character 

 tends to breed true, within a range of variation of 20 (or possibly 30) mm., 

 the minus variations, however, probably being greater than the plus ones. 



