420 RAYMOND PEARL AND M. R. CURTIS 



The anatomical relations of the ligaments and the distribution 

 of the muscle fibers suggest that it aids in the peristaltic move- 

 ments of the duct and may be of great importance both in the 

 reception of the yolk by the duct and in the extrusion of the 

 mature eggs. Cases 25 to 29 were planned to test the part 

 played by the ventral ligament. In case 25 it was cut and in 

 cases 26 to 29 all or a part of it was removed. 



Case 25 was a laying bird with an egg in the shell gland at 

 the time of operation. The round cord of muscle on the ven- 

 tral side of the head of the shell gland was cut. On the next 

 day the bird laid the egg which was in the shell gland at the 

 time of operation. She never laid again. The anatomical 

 effect of the operation is not known since the bird was accidently 

 sold more than a year after the operation. The operation did 

 not prevent the laying of the egg already formed but apparently 

 prevented the laying of any others. 



Case 26 was a three months old pullet with the oviduct in 

 infantile condition at the time of operation. The entire ven- 

 tral ligament was removed. The bird never laid. At autopsy 

 eight and one-fourth months after the operation it was found 

 that she had ovulated into the body cavity. The oviduct was 

 in the condition corresponding to the condition of the ovary but 

 there was no sign that a yolk had ever entered the duct. 



At the time of operation case 27 was a five and one-half 

 months pullet with oviduct still in infantile condition. Three- 

 fourths of a centimeter of the ventral ligament in the isthmus 

 region was removed. The bird developed normally and laid 

 several normal eggs. At autopsy four and three-fourths months 

 after the operation the ventral ligament was found in normal 

 condition at the upper end. The funnel attachments were 

 normal. The ligament was lacking entirely in the isthmus 

 region. On the ventral and lateral wall of the uterus closely 

 adhered to the wall was a thick mass of muscle which extended 

 across the uterus and sent fibers both dorsally and ventrally 

 along the uterus wall. Also there was a bundle of fibers which 

 passed along the ventral margin of the wall and on to the vagina. 

 The distribution of these fiber bundles was quite different from 



