Abdome?i. 175 



of the abdomen, uniting the axillary with the femoral sys- 

 tem, and a paraumbilical vein in the broad ligament of 

 the liver near the umbilicus, uniting the remains of the 

 umbilical vein in the ligament with the superficial veins 

 of the abdomen. 



5. The Linea Alba is a fibrous band stretching from 

 the pubes below, to the ensiform cartilage above. It is 

 the line along which the fibres of the aponeuroses on one 

 side decussate with those of the other. The linea alba has, 

 in addition to these decussating fibres, a small number of 

 vertical fibres. Below, there is a small band given off 

 from the under surface of the linea alba, to the upper bor- 

 der of the pubic bone, and this, situated behind the rectus, 

 is termed the adminiculum linea alba. The linea alba is 

 very narrow between the lower portions of the recti mus- 

 cles, but is broader above, the width in the former situa- 

 tion being one-eighth of an inch or less, whereas, in the 

 latter the average width is about one-quarter of an inch, 

 although, under certain circumstances, such as pregnancy, 

 etc., this width may be much increased. 



6. The Umbilicus is situated at the junction of the 

 lower two-fifths with the upper three-fifths of the linea 

 alba, and gives passage in the foetus, to the umbilical ar- 

 teries, to the allantois the inner portion of which be- 

 comes the bladder and the urachus in the adult, and 

 to the umbilical veins, right and left,. The umbilicus is a 

 fibrous ring in the substance, or rather composed of the 

 tissues of the linea alba, and, to it, the integument and the 

 superficial tissue, in front, and the peritoneum and the 

 transversalis fascia, behind, are firmly attached. 'The 

 umbilical ring is closed by scar tissue, the fibres of which 

 interlace, some being circular and others decussating from 

 side to side. The lower half of the umbilicus is stronger 

 than the upper half, since the remains of the umbilical ar- 

 teries and the urachus, converge to this lower half. 



