146 



PISKASKS OK I'Ori.TKV 



The egg advances into tlie more glandular and vas- 

 cular ]iart of the oviduct and here two otl.er layers of 

 albumen are secreted and deposited upon it. Each of 

 these is thinner and more watery than the one which 

 preceded. When the narrow part of the oviduct is 

 reached, two denser layers of albumen are excreted 

 forming the mcmbrana putaminis. Enclosed in this 

 manner, having acquired its ovate form and with the 



Fig-. 37.— Section of fowl's eg-g-; «, shell;/', menibrana putaminis; < , r, 

 layers of soft albumen; ./. clialazn>; <■, cicatricula and },'erminal vesicle;/, 

 air chamber. The outline liirure shows the yolk made up of layers ue- 

 posiled successively, k, cicatricula, /'. jrerminal vesicle. 



small end towards the cloaca, the egg enters the uter- 

 ine or shell -forming dilatation. The inner surface of 

 this portion of the oviduct secretes and deposits 

 upon tlie mcmbrana putaminis a thick white fiuid 

 which condenses, becomes calcareous and forms 

 the shell. The time required for the egg to ]iass from 

 the infundibulum to the uterus, in the common fowl, 

 is said to be from four to six hours, and it may remain 

 here from twelve to twenty liours. 



The color of the eg^g -shell depends upon i^igmental 

 matter secreted by particular follicles of tlie villous 



