474 



muscle fibers are quite large but as they pass ventrad toward the duct 

 they spread out in the ligament, breaking up into smaller bundles. 

 These smaller bundles anastomose frequently as they approach the 

 oviduct. At the attachment of this ligament to the oviduct these 

 bands of fibers continue around the duct. Most of them pass to 

 the medial side. 



The free ventral margin of the ventral ligament in the laying hen 

 is a solid muscular cord 3 to 6 mm in diameter. This cord becomes 

 heavier toward the caudal end of the ligament. From this cord bundles 

 of fibers extend on either side toward the oviduct in much the same 

 way as has already been described for the muscle bundles on the 

 medial side of the dorsal ligament. These fibers continue around the 

 oviduct. Some of the fibers pass to the medial and some to the 

 lateral side of the duct. 



Figure 1 is a photograph of the medial aspect of a piece of the 

 medial half of the caudal end of the isthmus and the attached liga- 

 ments of the oviduct of a laying hen. The lateral half of the oviduct 

 has been removed and the glandular layer scraped from the medial 

 half. The dorsal ligament lies toward the top and the ventral liga- 

 ment toward the bottom of the photograph. The right margin is the 

 anterior end of this piece of the oviduct and ligaments. The heavy 

 muscular mass which shows at the bottom of the photograph is the 

 caudal end of the free margin of the ventral ligament. From this 

 the fiber bundles pass out into the ligament and separate into smaller 

 bundles as the oviduct is approached. The cut ends of some of the 

 fiber bundles appear, rather indistinctly, where the lateral wall of the 

 duct was cut away. Some of the bundles can be traced into the 

 median wall of the oviduct where they lie above the circular fibers which 

 also appear in the photograph. In the dorsal ligament most of the 

 muscle fibers lie above the blood vessels but some of them accompany 

 these vessels. At the margin of the oviduct many of these fibers can 

 be seen passing above the layer of circular fibers. The origins of 

 these bundles are seen near the dorsal margin of the ligament. 



From the facts which have been brought out it appears that in 

 the domestic fowl the outer muscle layer of the oviduct is continuous 

 with the muscle fibers from the ligaments. This is similar to the 

 condition in mammals where the outer longitudinal layer of muscle 

 of the uterus develops from the muscle fibers in the broad hgament. 



In all vertebre animals the ovum at the time of ovulation is 

 theoretically cast out of the ovary into the abdominal cavity, but among 

 the different vertebrate class es there exists a whole series of structures 



