478 ARTHUR WILLIAM MEYER 



These (luotatioiis it seems also represent the consensus of 

 l)resent opinion in this matter and yet anyone who has carefully 

 observed the anatomy of the round and suspensory ligaments 

 of the liver in the domestic animals must have been impressed 

 with the fact that both are often entirely absent in comparatively 

 young animals and at least partially even if not entirely so, in 

 most very old animals. Moreover, it is more than probable 

 that the statements quoted are applicable onlj^ to the young of 

 some of the domestic animals. In several dogs three to twelve 

 months old only a vestige of the round ligament could be found 

 in the youngest animals and the suspensory ligament was al- 

 ready reduced to a very small triangular fold which represented 

 approximately })ut 2 per cent of its original extent. With some 

 slight qualifications this statement also applies to sheep, and to 

 a somewhat less extent also to cats, guinea pigs and rabbits. 

 In most of these animals the suspensory ligament at the time of 

 birth usually extends, of course, along the ventral abdominal 

 wall as far as the umbilicus and contains the umbilical vein in 

 its free margin. 



As has been stated elsewhei e by the writer, the intra-abdominal 

 lx:»rtion of the umbilical vein in the sheep cannot and does not 

 retract at time of birth, but remains filled with unclotted blood 

 sa^'e in its contracted j^ortion in the immediate vicinity of the 

 umbilicus where it contains a small clot. But soon after birth 

 the umbilical vein is freed from its attachment to the abdominal 

 wall as a result of degenerative changes and then undoubtedly 

 undergoes a delayed though a more rapid retraction and re- 

 gression after the manner described by Robin ('60), Haberda 

 ('96) and Baumgarten (77) in the case of the vein, and as is 

 true especially in case of the arteries in man. That this re- 

 traction and regression takes place comparatively rapidly is 

 well shown by the fact that it had resulted in ahnost complete 

 disappearance of the umbilical vein or so-called round ligament, 

 in lambs 5 to 7 weeks old. Since degeneration of the round and 

 suspensory ligaments are closely associated the condition of both 

 these structures as found in this lamb and in dogs will be de- 

 scribed with some detail. 



