194 Mammalia. 



the renal artery ; next comes tlie renal vein, and posteriorly, 

 of a rather dark color, is the Ureter. This tube, by which the 

 fluid secreted in the Kidney is conveyed to the bladder, is 

 directed obliquely backwards and inwards towards the middle 

 line along the dorsal wall of the abdomen, and passes vent r ad 

 of the common iliac artery of that side, and of the anterior 

 crural nerve which meets it at that point. A slight incision 

 should be made into the ureter close to the Kidney, and a 

 bristle passed along it. A probe should be passed up the 

 Rectum ; the sudden contraction of the last inch of the In- 

 testine noted ; and also the relative position of the anus. 



In Examination of the Diaphragm*, the Student should 

 note this muscle to be made up of a central tendinous (or 

 aponeurotic) part, and a fleshy periphery. The fleshy portion 

 takes its origin from the cartilages of all the false ribs and of 

 the last true rib, and from the superior (internal) surface of the 

 ensiform cartilage : its fibres converge towards the centre ; 

 and it is inserted between the ribs and the spine. In the 

 centre, close to the right of the tendinous part, is an opening, 

 foramen dextrum, through which passes the inferior vena 

 cava : to the left of the middle line, near the foramen dex- 

 trum, is a second opening, foramen sinistrum, for the passage 

 of the oesophagus and pneumo- gastric nerves : close up to 

 the vertebral column, ventrad of which the course of the 

 aorta has been already noted, are two large muscular pro- 

 cesses, of which the right is the longest and largest, termed 

 the crura or pillars of the Diaphragm, forming an inverted arch 

 beneath the aorta ; this arch is known as the hiatus aorticus, 

 and through it the thoracic duct passes, as well as the aorta. 



Dissection of the Thorax. The Pectoral muscles over 

 the chest must now be carefully cleaned away and reflected on 

 each side. First, let the skin be severed and reflected along 

 the arm ; secondly, let the Panniculus Carnosus be reflected 



* ha(ppaffaio, to separate two parts. 



