INHERITANCE OF FECUNDITY 199 



D. With 1 9 indicated to be of class 4 = JLdi . FLdi- 



9 Progeny 



Winter Production: Over 30 Under 30 Zero 



Observed 5 1 



Expected 6 



Mean winter production of 9 9 



in indicated class 39.40 eggs eggs 



All 9 Progeny 



Winter Production: Over 30 Under 30 Zero 



Observed 57 29 2 



Expected 62 26 



Mean winter production 48.16 eggs 13.81 eggs eggs 



Besides the families noted above o" D31 got one adult daughter 

 by each of two other females. Both these daughters had a winter 

 record of zero eggs and were apparently pathological. In any 

 event it was impossible to form any judgment as to their gametic 

 constitution or that of their dams. 



The general agreement between observation and expectation in 

 this large progeny group is clear. The apparent exceptions to 

 gametic expectation need some discussion. In the B matings 

 (class 299) the record shows 2^ in the 'Under 30' class where 

 none is expected. Actually out of the 30 individuals from these 

 matings only one daughter laid fewer than 30 eggs in the winter 

 period. There were, however, 3 individuals which laid exactly 

 30 eggs in this period. So, in accordance with the convention 

 adopted at the beginning, the record of 2f is made up as follows: 

 l+2+2+l=2|. The one bird under 30 with a record of 17 

 eggs was late hatched and probably represented a somatic fluctua- 

 tion. This bird was bred, but unfortunately got no offspring. 

 Her eggs were nearly all fertile but the embryos died during incu- 

 bation. 



Of the two birds with a zero winter record it may be said that 

 one (E96) was pathological, and on that account failed to lay. 

 The autopsy on this bird, which died April 13, 1909, showed that 

 it must have been functionally deranged for a long time preceding 

 death. Yet there was clear evidence of functional activation of 

 ovarv and oviduct at some time before death. In this case the 



