EAR-SIZE 



21 



Cross 4. — Lop-eared Female x Half-blood Lop Male. 



This cross is a sequel to crosses i and 3, a male rabbit j^roduced by 

 cross 3 being mated with the female lo]) used in cross i. This cross pro- 

 duced three-quarter-blood lops, the ear-lengths of which are indicated in 

 table 6. 



Table 6. — Cross 4. 



' 23 weeks. 



The range of variation in this mating is similar to that observed in a 

 mating of this same female with a lop-eared male (see table 2), viz, a 

 variation of between 20 and 30 mm. It is difficult to estimate it more 

 precisely, because the measurements recorded were made at such differ- 

 ent ages. Two of the offspring apj>ro.\imate the mid-parental conditions 

 both of ear-length and of weight, these two being (^319 and 9322. The 

 same is measurably true of a third individual, s 506. But 9 504 and 

 9 508 fall considerably short of the mid-parental ear-length and the 

 mid-parental weight; while c? 505 and 9 509 con.siderably exceed the mid- 

 parental ear-length, and approximate the mid-parental size. The greatest 

 deviation from the mid-parental ear-length is a minus one of 15 mm. 

 (recorded at the age of 18 weeks), but a \Aus deviation of nearly the same 

 amount (14.5 mm.) is also observed, though not until the age of a year 

 had been attained. The average deviation from mid-parental ear-length 

 is 9 mm. The lowest measurement, 180 mm., stands almost exactly 

 midway between the ear-length of the father (166 mm.) and the mid- 

 parental ear-length 195.5 mm.; while the largest measurement (210 mm.) 

 stands midway between the condition of the mother (225 mm.) and the 

 mid-parental ear-length. 



The result observed in this cross may be de.scribed as blending inheri- 

 tance, with fluctuation about the mid-parental ear-length, in about the 

 same degree as in the case of lop-eared rabbits i)urely bred. 



