78 THE STRUCTURE OF THE FOWL 



and the shell itself by the uterus.^ Possibly 

 the shell - cuticle and some of the colouring 

 matter is formed by the vagina. 



Though the right oviduct is abortive and 

 functionless, it is often represented by a rudi- 

 mentary tube opening into the cloaca. 



^ Dr. Raymond Pearl and Miss Curtis, from their observations 

 on the amount of albumen present at different periods before the lay- 

 ing of the egg, have come to the conclusion that fluid albumen 

 enters by osmosis through the shell-membrane even when the egg 

 has reached the uterus. Accordingly', albumen may continue to be 

 added to the egg until so much shell has been deposited as to stop 

 the process. 





