3 o LANDMARKS MEDICAL AND SURGICAL. 



see these muscular squares pretty plainly in some athletic 

 subjects. Much more frequently we see them, too much ex- 

 aggerated, on canvas and in marble. Artists are apt to ex- 

 aggerate them, and make the front of the belly too much like 

 a chess-board. It is lucky for them that all the world do 

 not see with anatomical eyes. 



A familiarity with the shape and position of these divisions 

 of the rectus is of importance, lest we should, in ignorance, 

 make a mistake in our diagnosis. A spasmodic contraction 

 of one of these divisions, particularly the upper, or a collection 

 of matter within its sheath, has been frequently mistaken for 

 deep-seated abdominal disease. 



In the erect position, the anterior superior spines of the 

 ilia are a little below the level of the promontory of the 

 sacrum. The bifurcation of the aorta is on about the level of 

 the highest part of the crest of the ilium. 



62. Umbilicus. The umbilicus is not midway between 

 the ensiform cartilage and the pubes, but rather nearer to the 

 pubes. In all cases it is situated above the centre of a man's 

 height. It is a vulgar error to say that when a man lies with 

 legs and arms outstretched, and a circle is drawn round him, 

 the umbilicus lies in the centre of it. This central point is in 

 most persons just above the pubes. 



In very corpulent persons two deep transverse furrows run 

 across the abdomen. One runs across the navel and com- 

 pletely conceals it. The other is lower down, just above the 

 fat of the pubes. In tapping the bladder above the pubes in 

 such a case, the trochar should be introduced where this line 

 intersects the linea alba. 



Although the position of the umbilicus varies a little in 

 different persons, as the abdomen is unusually protuberant or 

 the reverse, still, as a general rule, it is placed about the level 

 of the body of the third lumbar vertebra. Now, since the 

 aorta divides a little below the middle of the fourth lumbar, 

 it follows that the best place to apply pressure on this great 

 vessel is one inch below the umbilicus, and slightly to the left 

 of it (65). That the aorta can, under favourable circum- 

 stances, be compressed under chloroform sufficiently to cure 



