Imperforate Anus •' 1063 



part may be used. The skin from the inguinal region may be 

 drawn down tightly over the external ring, and sutures passed 

 through it and the internal and anterior margins of the ring, so 

 that the skin and dartos are thus firmly fixed to the deeper parts, 

 and the external abdominal ring virtually closed. Or, with heavy 

 silk, the margins of the external abdominal ring may be brought 

 together. 



The operation upon the pig is carried out in a similar manner. 

 The position of the scrotum in the pig renders it less difficult to 

 retain the intestines within the abdominal cawty. 



After the performance of the operation, the patient should be 

 allowed quiet and clean quarters. In the case of the foal, the 

 parts should be disinfected several times daily, but otherwise 

 should go undisturbed except in those cases where a pack of 

 gauze or other material has been inserted, as above recommended, 

 which should be removed in the course of 48 hours, when a suffi- 

 cient swelling will have taken place in the part to prevent the 

 prolapse of the intestine. For a time the animal should be fed 

 very lightly, in order to avoid distension of the abdominal cavity 

 and unnecessary pressure upon the parts. Should the ligature 

 about the cord become infected, a fistulous opening may result, and 

 necessitate cutting down upon the cord at a later date, and re- 

 moval of the ligature. Sometimes the ligature infection takes the 

 form of botryomycosis or schirrhous cord, and necessitates the re- 

 moval of the diseased cord. 



The age at which scrotal herniae should be operated upon will 

 vary according to circumstances. In the foal, unless there 

 is some reason to the contrary, such as strangulation, or growth 

 of the hernia, it should be postponed until the patient is eight to 

 twelve weeks old, but it may be performed at any age when cir- 

 cumstances may demand it. In the pig there is little, if any- 

 thing, to be gained by delay ; and the animal may as well be 

 operated upon at the usual age of castration. 



3. Imperforate Anus. 



In con.sidering the development of the embryo, we have 

 learned, on page 310, that at an early period in its history the 

 posterior gut ends blindly, and, opposite to it upon the external 

 surface, there appears a depression in 'the ectoderm known as the 

 proctodeal pit, which gradually becomes deeper while the wall be- 



