THE DIGESTIVE SYSTEM. 277 



portion becomes extremely congested, because of prevention 

 of the return of blood from it ; gangrene results, and may- 

 involve the peritoneum, in general extending from the 

 hernia as a centre. Internal herniae may exist for some time 

 without causing any appreciable inconvenience, except when 

 they become strangulated. When superficial, as in the 

 umbilical and ventral forms, they produce a swelling which 

 is soft, elastic, and often disappears as a result of properly 

 applied pressure. The tumour communicates a diagnostic 

 impulse to the hand when the animal coughs. Sometimes 

 the characters of the tumour differ from those above de- 

 scribed, as when the omentum is the part imprisoned ; then 

 the swelling is plastic, lobulated, and gradually disappears 

 on pressure. These lesions are mainly attributable to ex- 

 ertion and injuries. Thus they occur as a result of straining 

 during parturition, constipation, or coughing. The sym- 

 ptoms of strangulation are those of acute abdominal disorder, 

 stamping, kicking the belly, rolling, and violent straining, 

 whereby a contracted state of the rectum, which prevents 

 the entry of the hand, is produced (this has been thought 

 to be diagnostic), also general or local perspirations, rapid 

 breathing, and a quick, hard pulse. When gangrene 

 supervenes we have sudden cessation of the pain, anxiety, 

 running down pulse, marked fall of internal temperature, 

 and extreme coldness of the extremities, and, finally, a 

 delirous condition terminating shortly in death. Treat- 

 ment comprises return of the viscus, and prevention of 

 the recurrence of the hernia. 



Umbilical Hernia, Exomphalos, mostly is found in young 

 animals, and is not unfrequently congenital. In older 

 beasts it may result from injury and straining. Some- 

 times, through want of tone in the system, due to scro- 

 fulous and other debilitating tendencies, the umbilicus 

 remains iii a relaxed condition after birth, so that the 

 straining of the young animal to expel the hardened 

 meconium per anum is apt to cause hernia. We may 

 expect to find this condition also more frequently in 

 animals born prematurely than in those which have passed 

 the full time of utero-gestation. This form of hernia 



