PHYSIOLOGY OF THE OVIDUCT 421 



the distribution of those of a normal ventral ligament but 

 their contraction would be very effectual in diminishing the 

 size of the uterus and therefore in expelling the egg. 



Cases 28 and 29 were also young pullets from which portions 

 of the ventral ligament were removed before the first enlarge- 

 ment of the reproductive apparatus. Neither of these birds 

 ever laid. They were autopsied when in strictly non-laying 

 condition. The ventral ligament was lacking at the head of 

 the uterus. If they had ever passed through periods of repro- 

 ductive activity in which they ovulated into the body cavity, 

 they had completely resorbed all the yolks. These cases do not 

 therefore contribute to our knowledge of the function of the ven- 

 tral ligament since there was no proof that either bird had been 

 in laying condition. They, however, do agree with the results 

 from the other cases that if any portion of the ligament is removed 

 it is not replaced but all the remaining portions develop. In 

 case 27 described in the preceding paragraph there was, how- 

 ever, a compensating development of muscle fibers in the uterus 

 wall so that expulsion of the egg was possible. 



These experiments on the ventral ligament point strongly 

 to the conclusion that the action of the forward part of the 

 ligament is of great importance for the ovulation of the yolk 

 into the duct either by holding the funnel in position or by the 

 movements induced in the funnel. Since an egg cannot be 

 extruded unless it is formed, only two of these cases (25 and 27) 

 have any direct bearing on the question of the function of the 

 ligament in egg laying. Each of these birds could extrude 

 eggs after the operation on the ligament. In case 25 the liga- 

 ment was simply cut across. It is quite possible that this may 

 not have greatly interfered with the normal muscular action of 

 the muscle bundles in the uterus region. In case 27 there was an 

 unusual development of the muscle fibers on the wall of the 

 uterus. The contraction of these fibers would have much the 

 same effect as the contraction of the muscle bundles from the 

 ligament. This suggests that the muscle bundles contained in 

 and arising from the ventral ligaments are probably an important 

 part of the normal apparatus which expels the egg. 



