POUI^TRY NOTi;s. I9I 



tively all ,the factors which are concerned in the failure of the 

 unrecorded eggs to diminish during the year 1910-11. 



Direct observation indicates, however, that the chief cause of 

 the relatively high amount of unrecorded production towards 

 the end of this year (April, May and June) is to be found in 

 the behavior of certain cross-bred birds with respect to broodi- 

 ness. A number of these birds would show all the symptoms 

 of a severe attack of broodiness, yet after being put into the 

 broody coops to be "broken up" would continue to lay regu- 

 larly on the floor of the coop. This happened so many times 

 as to leave no doubt as to the fact, nor as to the relatively fre- 

 quent occurrence of this type of behavior among the cross- 

 bred birds. Owing to its unexpectedness we were hot prepared 

 this year to keep any exact records respecting the phenomenon. 

 To do this involves penning each broody bird alone. Next year 

 it is proposed to do this, and thus get precise records on a 

 matter regarding which we have so far only general observa- 

 tions. From the evidence now in hand it seems probable that 

 what we have here is an effect of the separate Mendelian segre- 

 gation of "broodiness" and "fecundity." In the care of these 

 F; birds of the peculiar behavior described we apparently have 

 individuals carrying both "high fecundity" and "high broodiness" 

 genes. The resulting behavior is a sort of compromise between 

 the • two tendencies. It might be thought that such a result 

 would be a physiological impossibility. This is not so. Para- 

 doxical the result certainly is, but plainly not impossible, since 

 it is actually the case that these birds have every physiological 

 attribute of broodiness, and yet lay regularly. In this connec- 

 tion it should further be said that a study of a large mass of 

 unpublished quantitative data on broodiness shows that the 

 physiological correlation between the function of laying and 

 that of brooding, is by no means perfect. Perfect "broodiness" 

 may be developed before any egg laying has occurred. Further 

 as in the present cases, broodiness and egg laying may coexist 

 over long periods. The writer hopes to be able shortly to pub- 

 lish in full the data on the physiology and inheritance of brood- 

 iness which have accumulated during the past four years. 



DISCUSSION. 



From the figures given above it appears that, on the average, 

 during the past three years, there lias been for every 100 eggs 



