BREEDING 93 



nuclei migrate as though repelled from the center toward 

 the margin. 



"After entering the infundibulum (funnel) the yolk remains 

 in the so-called albumen portion of the oviduct about three 

 hours and in this time acquires only about 40 to 50 per cent, 

 by weight of its total albumen. During its sojourn in the 

 albumen portion of the duct the egg acquires the chalazae 

 and chalaziferous layer, the dense albumen layer, and (if 

 such a layer exists as a distinct entity, about which there is 

 some doubt) the inner fluid layer of albumen."^ 



This albumen has a decided bactericidal property which is 

 highly important. "Without this defensive agency the 

 oviduct and therefore the eggs would be very liable to infec- 

 tion from microorganisms by way of the cloaca. Such an 

 infection would be very likely to greatly decrease the hatching 

 power of the eggs."^ 



"The contents of normal fresh eggs are as a rule sterile. 

 It is quite probable that an egg yolk may become invaded 

 before it leaves the ovary; but this is apparently an uncom- 

 mon occurrence, except when the ovary is infected with the 

 organism of bacillary white diarrhea. Little if any infection 

 takes place in the oviduct while the white and shell are being 

 deposited."' 



By the peristaltic contractions of the oviduct just back 

 of it, the egg is forced through the remaining sections of the 

 oviduct. "Upon entering the isthmus, in passing tiu-ough 

 which portion of the duct something under an hour's time 

 is occupied instead of three hours, as has been previously 

 maintained, the egg receives its shell membranes by a pro- 

 cess of discrete deposition. At the same time, and dming 

 the sojourn of the egg in the uterus, it receives its outer layer 

 of fluid or thin albumen, which is by weight 50- to 60 per cent, 

 of the total albumen. This thin albumen is taken by osmosis 

 through the shell membranes already formed. When it 

 enters the egg in this way it is much more fluid than the thin 

 albumen of the laid egg. The fluid albiunen added in this 



' Pearl and Curtis, Journal Experimental Zoology, vol. xii, No. 1. 

 2 Lillie, The Development of the Chick, 

 ' Re'ttger, Storrs Bulletin No. 76, 



