Dissection of Common Rat. 193 



Removal of Liver. The Liver should be now removed 

 from the Abdomen by cutting across the remaining ligaments, 

 and the vena cava (leaving it as long as possible, so as to be 

 easily distinguishable after removal of the Liver). 



The general structure of the Liver should be examined 

 under the microscope, sections being made in various direc- 

 tions, to expose the lobular arrangement with the intervening 

 interlobular veins, and the intralobular radicles ; the specimen 

 before us having been injected from the jugular vein, will 

 have the hepatic veins coloured by the injection*. 



The Kidney may be next removed for examination, by 

 dividinor its vessels about the middle : at the anterior ex- 

 tremity and rather underlying it is the supra-renal body, much 

 resembling the surrounding fat. The Ureter and the Renal 

 vein and artery lie close together in the longitudinal fissure, 

 or hilum, that marks the inner excavated border. Opposite 

 the fissure is a hollow in the interior of the Kidney, called a 

 sinus, into which the hilum leads. 



In order to see the interior, it will be necessary to cut 

 through the Kidney, from its concave to its convex border, a 

 little to the side of the vessels, and then to slit up the latter. 

 The section of the Kidney presents the typical Mammalian 

 arrangement, viz.: an external, granular, or cortical part, 

 and an internal, pyramidal, or medullary part ; but diflPers 

 from that in Man in that there is but a single papilla into 

 which all the renal tubuli open. The investigation of the 

 secreting tubes, &c., must be conducted with specially injected 

 specimens of this organ ; and is not easily conducted with the 

 Kidney of a small animal as that before us. 



Returning again to the body of the animal, the student 

 should trace hack the Ureter from the Kidney left in situ. 

 Of the three vessels in the hilum, that which is anterior is 



In order to expose the persistent companionship of the vena porta, hepatic 

 artery, and hepatic duct, the liver must he specially injected and hardened. 

 Vide Introduction, 



CC 



