THE THIGH. 43 



keep the umbilicus in view ; in cases of difficulty feel the 

 urethra through the rectum, to ascertain whether the instru- 

 ment be in the right direction. Attention to these rules 

 diminishes the risk of making a false passage, an injury 

 which under great delicacy in manipulation ought never to 

 happen. 



Urethra in the child. In children the membranous part 

 of the urethra is, relatively speaking, very long, owing to the 

 smallness of the prostate. It is also more sharply curved, 

 because the bladder in children is more in the abdomen than 

 in the pelvis. It is, moreover, composed of thin and delicate 

 walls. The greatest gentleness, therefore, should be used in 

 passing a catheter ; else the instrument is likely to pass 

 through the coats and make a false passage. Hence the 

 advantage of being able to ascertain through the rectum 

 whether the instrument be in the right track and moving 

 freely in the bladder, which can also be easily felt in 

 children, 



THE THIGH. 



93. Poupart's lig-ament, or crural arch. Mark the 

 anterior superior spine of the ilium, the spine of the pubes, 

 and define the line of ' Poupart's ligament ' which extends 

 between them. This line is one of our guides in the diagnosis 

 of inguinal and femoral herniae. If the bulk of the tumour 

 be above the line, the hernia is probably inguinal ; if below 

 it, femoral. The line is not a straight one drawn from the 

 spine of the ilium to the spine of the pubes, but slightly 

 curved, with the convexity downwards, owing to its close 

 connection with the fascia lata of the thigh. In many per- 

 sons it can be distinctly felt ; in nearly all its precise course is 

 indicated by a slight furrow in the skin. 



For the points about the spine of the pubes, refer to para- 

 graph 69. 



94. Furrow at the bend of the thig-h. When the 

 thigh is even slightly bent, there appears a second furrow 

 in the skin below that at the crural arch. This second 



