EGGS OF BIRDS. 



253 



131 



upper part of the oviduct, with the coating of dense albumen 

 continued into the chalazoe; B, the outstretched chalaza3 from 

 opposite sides of the yolk, showing the opposite turns of the 

 spiral; c, an egg from above the middle of the oviduct, mth the 

 first layers of soft albumen deposited upon the chalaziferous 

 membrane and chalaza3. 



The albumen is rapidly added in the more glandular and vas- 

 cular part of the oviduct, by 

 the ridsfes of follicles which 

 correspond in direction with 

 the spiral course of the egg ; 

 and, when it has arrived at 

 the narrower part of the 

 o\dduct called the isthmus, 

 denser layers of albumen are 

 again excreted, forming the 

 ' membrana putaminis,' fig. 

 130, A, d. So inclosed, and 

 having acquired its ovate 

 form with the small end to- 

 ward the cloaca, the egg 

 passes into the ' uterine ' or 

 shell-forming dilatation, fig. 

 128, k. 



Artificial coagulation of 

 the albumen or ' white ' of 

 an eo;2: enables one to de- 

 monstrate its disposition in 

 spirally deposited layers. 

 It is at the latter stage of 

 the eofo^'s formation that the 

 spiral structure of the cha- 

 lazae becomes apparent. The 

 time of the passage of the 

 ecro- from the infundibulum 

 to the uterus, in the Com- 

 mon Fowl, is from four to 

 six hours. Here it may remain from twelve to twenty hours. On 

 entering the ' uterus,' a thickish white fluid exudes from the inner 

 surface of the cavity and condenses on the ^ membrana putaminis,' 

 forming thereon a cellular matrix in which soon appear particles 

 of calcareous matter, which from the shape they assume in the 

 interstices of the matrix appear to be crystalline. 



stages of egg in oviduct, cccriii. 



