INHERITANCE OF FECUNDITY 245 



Two of the class 7 B.P.R. males (562 and 567) were mated with 

 two Fi blacks whose sire was C.I.G. d' 558. It has already been 

 sliown from the pure Cornish and Fi matings that this Cornish 

 cf 558 had the gametic constitution JLiU ■ fkk- In respect to 

 fecundity his Fi daughters in the 'Under 30' class were gametically 

 of two types: viz., fLik . FUk and fLik . FLik. None of the 

 second type were used in these matings. Only a small progeny 

 resulted from the mating of the two females of the first type. The 

 actual results were as follows: 



9 Progeny 



Winter Production: Over 30 Under 30 Zero 



Observed 2 4 



Expected 3 3 



Mean winter egg production of 



all 9 9 in indicated class. .... 38.00 eggs 8.5 eggs 



B.P.R. cT 569 was mated with a black Fi 9 sired by C.I.G. 

 cf .529. Only two daughters were obtained. Both made winter 

 records under 30 eggs. The number of daughters is too small to 

 have any significance, or to make classification possible. 



Putting all the results together (with the exception of the two 

 individuals just noted as not capable of classification) we have: 



Fi9 Progeny from matings of B.P.R. d" d" X Black Fi 9 9 



Winter Production: Over 30 Under 30 Zero 



Observed 7 18 



Expected 12.5 12.5 



Mean winter production 37 . 29 eggs 10 . 55 eggs 



There is clear evidence of segregation here but there is a defect 

 in the observed numbers in the 'Over 30' class. After careful 

 study of all the facts a possible explanation of this appears to me 

 that the absolute degree of fecundity manifested somatically 

 when Li is present in the gametes may be less if the Li comes from 

 a Cornish Indian Game than if it comes from a Barred Plymouth 

 Rock. In other words it appears to be the case that what ma}^ be 

 called the absolute fecundity value or worth of Li is different in 

 these two breeds. An indication that this is the case is found in 



