98 ENTOZOA FOUND IN MAN, 



reason for this is that, owing to the intestines and 

 the stomach being almost entirely surrounded by the 

 peritoneum, there are only certain parts at which 

 the worm can pass out of the intestine without 

 getting into the peritoneal cavity, and this reason 

 will also account for the fact that the number of 

 cases which have been recorded of the passage of 

 lumbrici into the peritoneum is very large, as com- 

 pared with those cases in which the worms escaped 

 by traversing the abdominal walls. 



Sometimes, as a result of some lesion of the 

 intestme, such as inflammation, ulceration, or gan- 

 grene, tumours are formed in which lumbrici are 

 contained. The position of these tumours, which are 

 usually situated near to the umbilicus or the groin, 

 favours the inference that they most frequently 

 result from strangulated hernia. 



These tumours may be divided into three classes. 

 In the first the worm, which has escaped from the 

 intestine, appears to be the sole cause of the inflam- 

 mation and suppuration of the parts which cover it. 

 When the abscess is opened, pus of a healthy cha- 

 racter issues from the opening, together with one or 

 more worms, but no excrementitious matter ; no 

 foecal fistula supervenes, and a speedy cure is effected. 



In the second form, both the worms and the 

 foecal matter which have issued from the intestine 

 take an equal part in the formation of the tumoiu- ; 

 the opening remains fistulous for a variable period ; 

 and the discharge of foecal matter, and sometimes of 

 additional worms, furnishes a proof of the perma- 



tion between this mannei' of exit aud the relative frequency of 

 hernia in difi'erent parts of the abdomen at different ages. 



