38 



INHERITANCE IN RABBITS 



because based on too few individuals (in 4 cases, a single litter each time). 

 The Belgian hare was heavier than the short-eared stock used, and it 

 will be seen that, in all cases, her descendants exceed in size animals of 

 the short-eared series having a like amount of lop blood. Further, a 

 mixture of short and Belgian blood tends to produce a rabbit intermedi- 

 ate in weight between those of the short and of the Belgian series, respec- 

 tively. (See table 26, right section.) All these observations confirm the 

 idea that body-weight is a character blending in its inheritance. 



Table 26. — Size at 18 weeks of age of rabbits of different proportions of lop 

 ^^ blood," from crosses with short-eared, with the Belgian hare, or with both. 



1 This is certainly too low, for in litter 70, table 2, mating 3, it was surpassed by three of the 

 five rabbits of the litter, already at 14 weeks of age. The average given (1,743) is for the two ani- 

 mals, 6^179 and 9 180 (table 2, mating i). 



2 At 14 weeks. 



When the parents differ in size, the young are clearly of intermediate 

 size, but our observations are too incomplete to show in most cases whether 

 the size is midway between that of the respective parents or not. Prof. 

 W. C. Sabine has kindly pointed out that if linear dimensions give a mid- 

 parental condition (the mean of the respective parental conditions), then 

 we should expect the weights to be less than the mean of the parental 

 weights, provided the proportions of parts are the same in all cases. But 

 the proportions of the parts are different in the two parents, when rabbits 

 of different size are mated with each other, and the proportions in the off- 

 spring are unmistakably intermediate between those of the respective parents. 



This, perhaps, accoimts for some of the peculiarities observed in com- 

 paring weights of the rabbit c? 248 with those of his parents, and with 

 the mid-parental weights. All three rabbits were fully grown (2 or more 

 years old) when the observations were made, and these are fairly com- 

 plete. The maximum body-weight recorded for S 248 was somewhat 



