POULTRY NOTES I9II-I913. 165 



isthmus. Not yet having entered the isthmus the egg had no 

 shell membrane upon it. It consisted merely of a yolk sur- 

 rounded by albumen. The outermost layer of this albumen 

 was dense and corresponded to layer c described above. There 

 was no trace of thin albumen (layer d) 'on this egg although 

 it was just on the point of leaving the so-called albumen region 

 of the oviduct. 



The successive autopsy records reported in the complete 

 paper show that beginning with an egg 11 cm. away in front 

 of the isthmus and going downwards in the duct until the actual 

 boundars' of the isthmus is reached, there is no qualitative 

 change in the albumen secretion. Whatever albumen is added 

 to the egg immediately prior to the formation of the shell 

 membrane, is of the dense fibrous variety (layer c), so far as 

 direct observation indicates. 



In cases where one-half of the egg lies within the isthmus 

 and bears a membrane, while the other half is in the albumen 

 portion and has no membrane, it can plainly be seen that the 

 shell membrane is deposited directly on the outer surface of 

 the thick albumen (layer c) and that no trace of the thin albu- 

 men (layer d) is present at the time the membrane is formed. 



A detailed and careful study of the weights of the several 

 parts of the egg (yolk, albumen, shell membranes') in eggs 

 taken from different levels of the oviduct, leads to the following 

 results. 



When the egg leaves the albumen portion of the oviduct it 

 weighs roughly only about a half as much as it does when it is 

 laid. Nearly all of this difference is in the albumen. Thus 

 these weighings fully confirm the conclusion reaches from di- 

 rect examination of the eggs, as already described. The 

 evidence shows that the egg gets all of its thin albumen 

 (layer d), which constitutes nearly 60 per cent by weight of the 

 total albumen, only after it has left the supposedly only albu- 

 men secreting portion of the oviduct, and has acquired a shell 

 albumen, and the shell is in process of formation. 



The weighings show that in general the farther down the 

 oviduct the egg proceeds the more albumen it gets. Very nearly 

 one-half the total weight of albumen of the- completed egg is 

 added in the uterus, an organ hitherto supposed to be entirely 



