HISTOI.OGY OF TUt OVIDUCT OF THE DOMESTIC HE^N. 423 



region. Consequently the funnel has been regarded as an organ 

 for grasping the yolk at the time of ovulation but without any 

 secretory function. In the present study we have been able to 

 show that groups of gland cells occur at the base of the epithe- 

 lial folds throughout the funnel region. We have further 

 shown that structurally these glands of the funnel are homol- 

 ogous with the tubular glands found in other parts of the 

 oviduct. On the other hand the unicellular glands found in the 

 epithelium of other parts of the duct do not occur in the anterior 

 part of the funnel. 



The presence of glands in the funnel leads, of course, to the 

 presumption that this region secretes a portion of the substance 

 enveloping the yolk. In the normal hen's egg there is next to 

 yolk a very thin layer of dense albuminous substance. This is 

 known as the chalaziferous layer and is continued at the poles 

 of the egg into the familiar structures known as the chalazae. It 

 thus appears not unlikely that the chalazae and their corres- 

 ponding albuminous layer may be secreted in the funnel. I 

 know of no instance in the literature where an egg has been 

 observed in the funnel region before it has entered the albumen 

 secreting portion. 



In the albumen secreting portion of the oviduct there are two 

 sets of glands present, viz. : the tubular glands and the uni- 

 cellular glands of the epithelium. As Pearl and Curtis ('12) 

 have shown, the albumen portion secretes only the demise albu- 

 men. The outer layer of fluid albumen is not secreted in this 

 region. Apparently both sets of glands take part in the forma- 

 tion of this dense albumen. 



The distinctive function of the isthmus is to secrete the shell 

 membrane. A very beautiful demonstration of this act was 

 first described by Coste ('47). Coste described an egg, one end 

 of which had just entered the isthmus. This end of the egg 

 was covered with a thin layer of membrane, while the end still 

 in the albumen portion was naked. This account of membrane 

 formation has several times been confirmed in this laboratory, 

 (Pearl and Curtis, '12). A further very interesting observa- 

 tion is reported by Pearl and Curtis,, viz. : that in the so-called 

 albumen portion of the oviduct only about 40 per cent, by 

 weight, of the total albumen is formed. During the passage of 

 the egg through the isthmus it receives in addition to the shell 

 membrane, 10 to 20 per cent more of the total albumen. It is 



