492 ARTHUR WILLIAM MEYER 



processes occur at somewhat different times in all animals. The 

 differences that exist are of degree rather than of kind. 



It is not at all uncommon to find a small amount of blood 

 near the free ends of the torn hypogastric arteries in the lamb 

 but such was, of course, never the case in animals in which the 

 vessels are ruptured extra-abdominally and in which only a 

 delayed retraction occurs. The presence of extensive clots within 

 the vessels was rare in the lamb l3ut common in the other 

 animals for in them an effective obliteration of the luniina was 

 probably made difficult by the fact that the vessels remained 

 attached to the umbilicus thus making contraction of the intra- 

 abdominal portions more difficult. Since the presence of clotted 

 or unclotted blood must of necessity, prevent rapid obliteration 

 of the lumen of a vessel and delay retrogressive changes in it 

 it does not seem probable that the presence of clots could aid 

 much in preventing hemorrhage as Gmelin thought. 



Since the ends of the retracted hypogastric arteries in lambs, 

 often projected freely into the peritoneal cavity rupture of the 

 peritoneum must, of course, have taken place. Since the evacu- 

 ation of the bladder takes place at intervals before these vessels 

 become detached without producing this lesion and since the 

 end of only one of the retracted vessels may project intra-peri- 

 toneally in the newborn lamb, it does not seem likely that the 

 combined force resulting from the retraction of the detached 

 arteries and the contracting bladder is sufficient to produce a 

 rupture of the overlying peritoneum. It is true that in the lamb 

 the immediate, sudden elastic recoil of the arteries may be asso- 

 ciated with or even stimulate, the evacuation of the bladder 

 which usually occurs soon after or even during birth, but these 

 combined forces could scarcely rupture the peritoneum. Hence 

 it seems quite obvious that the latter is torn as a result of the 

 outward traction produced at the time of rupture of the cord. 

 This conception is also in accord with the statement of Henne- 

 berg that the arteries tear intra-abdominally although as pre- 

 viously stated I am inclined to believe that rupture in ruminants 

 occurs extra-abdominally but in portions of the vessels which 

 previous to traction and rupture were intra-abdominal. 



