372 MAINK AGRICULTURAL EXPERIMENT STATION. I912. 



B.P.R. $ 569 was mated i^vith a black Fl 5 sired by C.I.G. 

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

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

 ot 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 : 



Fi 2 Progeny from matings of B.P.R. c? c^ X Black F, 9 2 



Winter Production: Over 30 Under jo Zero 



Observed 7 18 o 



Expected , 12.3 12.5 



Mean winter production 37-29 eggs 10.55 eg&s 



There is clear evidence of segregation here but there is a de-^ 

 feet 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 may be called the absolute fecundity value or worth of La 

 is different in these two breeds. An indication that this is the 

 case is found in the following figures. In the case of pure 

 C.I.G. matings the factor L2 is not present. All females in the 

 'Under 30' class are therefore either L^h or LJa in type. The 

 mean winter production of all pure C.I.G. 9 9 in the 'Under 

 30' class is 10.22 eggs. The mean winter production of all pure 

 B.P.R. 5 2 in the 'Under 30' class is 15.61 eggs. The probable 

 errors in both cases are less than i. Of course the 'Under 30' 

 class in the case of B.P.R. 2 2 includes the following gametic 

 types : L^h, LiL\, hh, and 1,2/2. The last two C[0 not occur in the 

 pure C.I.G.'s. Granting the greatest conceivable iniluence to 

 this, it is still evident that the 7vi factor of a Barred Rock prob- 

 ably means a higher winter production than the Li of a Cornish 

 Game. But if this is true then plainly the division or upper 

 limiting point for the low fecundity class should not be at 30 

 eggs but at some lower point in the case of females bearing Z.i 

 from a Cornish Indian Game source. If it be kept at 30 eggs 

 for all birds, and there is a difl^erence in the absolute fecundity 

 value of the factors, then plainly some birds will be put in the 



