BROODINESS IN DOMESTIC FOWL. 



103 



Table I. — Kinds of Offspring expected from all Possible Kinds of Matings. 



Parents. 



Offspring. 



Both parents broody 



Both parents non-broody, 



One parent broody, the other non-broody. 



All broody. 



All non-broody.* 



Part broody, part non-broody. 



AH broody.* 



All non-broody. 



Part broody, part non-broody. 



X\\ broody. 



All non-broody.* 



Part broody, part non-broody. 



Of the nine possible groupings between parents and offspring, six have 

 been reahzed in our experience. Those marked ■nith an asterisk (*) have 

 not been reahzed. Two of the three unreaHzed possibihties should be 

 realized eventually, and the third, all non-broody offspring from broody 

 parents, is not expected, as is explained beyond. 



The preceding table, as well as the ratios in which the offspring occur. 

 Table II, does not agree ■uith the assumption that broodiness is a simple 

 Mendelian dominant and non-broodiness a simple recessive in all instances 

 as Hurst (1905) supposed. If non-broodiness were a simple Mendehan 

 recessive, then the son of a non-broody hen should throw either all non- 

 broodies or half non-broodies when bred to non-broodies, but this does 

 not always happen. Moreover, the establishment of a non-broodj^ strain 

 should have been a much simpler matter than it has proved. 



