inheritance; of fecundity in domestic fowl. 339 



Matings: A. With 4 ? $ indicated to be of class I = fLiL-.. Fhk. 



All ? Progeny 



Winter Production: Over so Undergo Zero 



Observed 13 5 2 



Hxpected 15 5 



Mean winter production of all 



$ ? in indicated classes Sy-OO eggs 25.20 eggs eggs 



The facts regarding the two zero birds here are of interest. 

 According to theory no bird of this class should appear from 

 any of these matings. One of these zero birds, EiQ2, laid her 

 first egg A'larch 4, 1909, and proved thereafter, during the re- 

 productive period f March i to June i) to be a fairl}^ good 

 layer, with a total production for the period of 51 eggs. 



Her laying during this and the subsequent summer period 

 both in respect to its amount and its distribution, impresses one 

 as like that of a bird carrying L.. rather than like that of a "gen- 

 etic' zero winter layer lacking this factor. T am of the opinion 

 that this was the case. This bird, on such a view, would repre- 

 sent an extreme physiological variant in respect to the beginning 

 of laying. While apparently bearing Li this factor did not come 

 to expression until much later than under normal circumstances. 



The other zero bird was pathological in respect to her repro- 

 ductive organs. She never laid an egg and died July 16, 1909. 

 The autopsy record is as follows, plainly showing that the zero 

 record of this bird cannot be taken as any indication wdiatever 

 of her gametic constitution in respect to fecundity. 



Autopsy of E 318; July 16, 1909. Body weight, 1730 grams. Hatched 

 March 31, 1908. Oviduct small : parts of it contained masses of hard- 

 ened secretion. Ovary with no large oocytes. One small yolk resorb- 

 ing. Body cavity filled with masses of hard yolk enclosed in peritoneal 

 sacs. Some of these masses were small and attached to mesentery. 

 Some were large. A large mass filled the dorsal part of body cavity 

 on left side pushing over by a neck and connected by this with a similar 

 mass on right side. This was partly hollow and in the cavity the sur- 

 face was covered with a fruiting- fungus resembling Penicillium. The 

 peritoneum covering the masses of hard yolk formed adhesions with the 

 viscera so that the intestine and oviduct were a bundle of adhesions 

 clinging to these yolk masses. 



It is only possible to summarize separately class 3 i matings 

 for class i females. This is done in table 21. 



