124 SPRINGTIME SURGERY 



generally accepted theory. The navel cord of the 

 foal and the calf are much more ample compara- 

 tively than that of the child or of the young of car- 

 nivora. The environment in which young are 

 born differs widely, and the care bestowed upon 

 the navel cord by the mother also varies greatly. 

 The attitude of the young animal further changes 

 conditions materially. 



In herbivora the navel cord is normally rup- 

 tured by linear tension. It generally parts at a 

 particularly fra,il point near the umbilicus. The 

 cord being tensely stretched at the moment of 

 parting, the umbilic arteries are much elongated 

 and when they finally break, the proximate ends 

 recoil, retracting into the abdominal cavity, draw- 

 ing with them in an inverted state the surround- 

 ing loose perivascular tissue. The ruptured 

 arterial stump is thus promptly withdrawn from 

 the exterior where it might become infected, and 

 the inverted, adherent connective tissue at once 

 aids the contracting arterial stump in controlling 

 the hemorrhage. The umbilic vein, or veins, col- 

 lapse. The stump of the urachus retracts within 

 the abdominal cavity between the two arterial 



