INBREEDING IN RELATION TO EGG PRODUCTION 261 



If the unsatisfactory character of the above six hens from the egg production 

 standpoint was due to low vigor resulting from inbreeding, mating with such a 

 male would bring the stimulus of heterosis to the progeny and might enable the 

 daughters to lay more eggs than their mothers. On the other hand, if the out- 

 side male used lacked the necessary inherited characteristics responsible for high 

 production, the daughters would be low producers even though they carried the 

 stimulus of heterosis. 



Results of 1923 Matings 



From the six hens mated to the above described cockerel, 82 progeny resulted. 

 It is interesting to note the sex ratio of the chicks surviving to an age when the 

 sex could be distinguished by external appearances. In the 72 chicks the sex of 

 which was recorded, there were nearly twice as many males as females. These 

 high sex ratios were not due to a pronounced higher post-natal mortality in female 

 chicks because more than half of all chicks hatched were males. There may have 

 been a higher death rate of females in the shell but this record was not obtained. 

 The seasonal effects on sex ratio pointed out by Jull (1924), as well as the low an- 

 tecedent production of the mothers, may in part explain the higher sex ratio 

 observed. 



