EAR -SIZE 



23 



size and yet lo attain a normal or nearly normal general size. It is not 

 to be expected, however, that such an animal will transmit to voung reared 

 under normal conditions the diminished ear-size which it shows, but rather 

 the ear-size which it would have attained harl it been reared under normal 

 conditions. 



Table 8. — Cross 5. 



Parents: 



?i67 



cJ>i79(lop) . 

 Mid-parental 



Offspring: 

 Litter i — 

 c^437 



9438 



Litter 2 — 



^^566 



crs68 



(^'sfig 



9570 



Litter 3 — 

 9644 



(^645 



9646 



9647 



9648 



cr649 



Ear- 

 length. 



mm. 



130 

 210 

 170 



1 184 

 / 200 



I 177 

 / 185 



Weight. 



gms. 



2,55° 

 3.410 

 2,980 



2.550 

 3.140 

 3,510 

 3. no 



Age. 



Adult. 

 Do. 

 Do. 



20 weeks. 

 30 weeks. 

 20 weeks. 

 30 weeks. 



18 weeks. 

 Do. 

 Do. 

 Do. 



20 weeks. 



7 months. 

 20 weeks. 



Do. 



Do. 



Do. 



Do. 



Cross 6. — Half-blood Lops Mated inter se. 



The same female half-blood lop already mentioned (9167, cross 8), 

 was mated with a male produced by cross i (^"248). Their young con- 

 stitute an F2 generation of half-blood lops. 



In this litter the deviations from the mid-parental ear-length are all, 

 with one exception, positive (upward). This result accords with that 

 observed among the young of this same mother (9 167), in connection 

 with cross 5. She evidently transmitted a greater car-length than she 

 manifested. 



The range of variation, 35 mm., while high, docs not exceed that found 

 among lop-eared rabbits mated inter se, as is clear from a comparison of 

 fig. 2 with fig. 3, the former showing growth-curves for lop-eared rabbits, 

 the latter for the litter of F, half-blood rabbits under consideration. The 

 range of variation in this cro.ss also agrees exactly with that observed in 

 cross 5, in which the same mother was matccl with a full-blood lop. We 

 get, therefore, from this case no evidence of Mendelian sj)litting as regards 

 the character ear-length. 



