REPRODUCTION IN THE DOMESTIC FOWL. 1 93 



Specimen 9 was found with the craniad or blunt end of the 

 included egg 14 centimeters from the funnel mouth. The 

 normal hard-shelled egg had a shell membrane around the shell. 

 There was no albumen between the shell and this membrane. 

 Either the egg had received this membrane on its way up or 

 it had been carried into the albumen-secreting region and im- 

 mediately canied back into this isthmus and after receiving 

 the membrane had been carried back up the duct nearly to the 

 funnel mouth. This had probably happened only a short time 

 before death, since there was no albumen formed around the 

 outer shell membrane. 



A diagram of specimen 10 is shown in Fig. 6. From the 



FIG. 6. Showing the structure of double egg No. 10. a = albumen; I = granular 

 shell material; m = egg membrane; s = shell; y = normal yolk. 



figures it may be seen that the enclosed hard-shelled normal 

 egg is not entirely surrounded by all of the envelopes of the 

 enclosing egg, but the second egg membrane filled with albumen 

 forms a cap which covers the blunt half of the enclosed egg. 

 At the posterior pole of che egg the enclosing cap of egg mem- 

 brane is continued into a stalk also filled with albumen. This 

 stalk is folded down against the side of the egg. The whole 

 egg is covered with a continuous layer of granular shell material. 

 The stalk of the including egg must have been folded down before 

 this shell was secreted as the under side of the stalk and the 

 part of the egg membrane against which it lay were free from 

 shell. 



