DISEASES OF POULTRY. 



145 



Fijj. 34. Fig. 35. Fig. 36. 



Fig. 34. — Egg from upper part of oviduct with coating of dense albumen 

 called raembrana chalazifera continued into the chalaz;i:-. Fig. 35. — Out- 

 stretched chalazas from opposite sides of the yolk showing opposite turns 

 of the spiral. Fig. 36— Egg from above middle of oviduct with first layers 

 of soft albumen. 



upper portion of the oviduct and soon after the egg 

 escapes from the ovary. Having entered the oviduct 

 the ovum is propelled with a rotary motion by the 

 peristaltic contractions of that tube, towards -the 

 cloaca. The contact of the ovum stimulates the lin- 

 ing membrane of the oviduct to secrete first a dense 

 laj'er of albumen which is deposited upon the vitelline 

 membrane and is continued thread -like from each pole. 

 These threads or filaments are the chalazai and the 

 dense layer of albumen with which they are connected 

 is the membraua chalazifera. As the egg rotates in 

 the oviduct the chalazce become twisted in opposite 

 directions, and the one next the small end of the egg 

 finally adheres more or less to the membrane lining 

 the shell at that point. 



