APPENDICITIS. 377 



cylindrical form. These may arise in connexion with the out- 

 growth of the allantois from the bowel, an explanation which 

 brings them in line with similar strictures of the oesophagus, 

 duodenum, and ileum. 



Occasionally the rectum ends blindly two inches or more 

 above the anus. The mere persistence of the cloacal septum is 

 insufficient to account for so much separation of the two tubes. 

 In such cases either a part of the rectum has been obliterated, 

 and may still be represented by a fibrous cord, or the condition 

 may be due to a complete failure in the down-growth of the 

 post-allantoic portion of the gut. 



If the rectum retains its connexion with the allantois, and the 

 anal canal is not formed, the bowel may open into the bladder or 

 upper part of the vagina. Abnormal communications with the 

 urethra, or openings in the region of the vulva, indicate that the 

 bowel has retained its communication with the front part of 

 the uro-genital sinus. Communication of the rectum with a 

 spina bifida suggests the persistence of a neurenteric canal. 



Discharge of bowel contents from the umbilicus are in some 

 cases due to a wound of a prolapsed coil of intestine during 

 division of the umbilical cord. In other instances a Meckel's 

 diverticulum is present and patent. 



It has been suggested that a coil of bowel is sometimes ensnared 

 in the umbilical ring during foetal life and so obliterated. 



APPENDICITIS. 



The situation of the local tenderness and the local swelling 

 caused by appendicitis will depend upon the position which 

 the appendix happens to occupy. 



The spot at which the vermiform appendix springs from the 

 inner and back part of the caecum may be indicated with sufficient 

 accuracy by taking a point one inch below the intersection of the 

 right Poupart and the intertubercular planes. (Fig. 49, p. 362, 

 also Fig. 54, p. 429.) The "lie" of the appendix itself is 

 inconstant, and cannot be predicted with accuracy. 



