PHYSIOLOGY OF THE OVIDUCT 419 



3. Removal of the larger part of the duct 



In cases 15 to 20 the oviduct was almost entirely removed. 

 In most cases a portion of the funnel and a portion of the vagina 

 were left. All these ducts were far from laying condition at 

 the time of the operation. Case 17 was just beginning to en- 

 large for its first laying period. It was only 15 cm. long. The 

 others were in infantile or non-laying condition. An exami- 

 nation of the autopsy records made from seven months to four 

 years and eight months after the operation shows, first, that 

 whatever portion had been left at the time of operation had 

 remained, and second, that at the time of autopsy it exhibited 

 the condition which one would expect to find for that portion 

 of the entire oviduct in a bird with a similar condition of the 

 ovary. This shows that the removal of the greater portion 

 of the oviduct does not cause the atrophy of any remaining 

 portion. In fact any part of the duct not removed apparently 

 passes through growth and cyclic changes associated with the 

 periods of ovarian yolk production exactly the same as though 

 the duct were intact. This result was obtained also by Sell- 

 heim ('07). 



4. Section or removal of all or a part of the ventral ligament 



The peritoneal sheet which enfolds the oviduct projects as 

 a fold along the ventral margin of the duct. In this fold of 

 peritoneum there is developed a considerable amount of smooth 

 muscle. This peritoneal fold with its contained muscle has 

 been described by one of the authors (Curtis '10) as the ventral 

 ligament of the oviduct. In a laying bird the extreme ventral 

 margin of this ligament is a solid muscular cord, three to six 

 millimeters in diameter. It becomes heavier toward its caudal 

 end. 



Muscle bundles pass from it to the duct where they are con- 

 tinuous with fibers in the longitudinal muscular layer of the 

 wall. Other bundles pass to the colon and cloaca. Large 

 bundles also cross the uterus and attach to the body wall muscles 

 in the anal region. The forward end of the Hgament suspends 

 the backward prolongation of the funnel lips. 



