To demonstrate the anatomy of the renal organs proceed as follows:

1. Kill a rat in any merciful way; placing it under a bell-jar with a sponge soaked in ether is a good method.

2. Open the abdomen of the animal, remove its alimentary canal, and cut away (with stout scissors) the ventral portion of the pelvic girdle. The dark-red kidneys will then be easily recognized on each side of the dorsal part of the abdominal cavity, the right one nearer the head than the left.

3. Dissect away neatly the connective tissue, etc., in front of the vertebral column, so as to clean the inferior vena cava and the abdominal aorta. Trace out the renal arteries and veins.

4. Find the ureter, a slender tube passing back from the kidney towards the pelvis: it leaves the inner border of the kidney behind the vein and artery; and lying, at first, at some distance from the middle line, converges towards its fellow as it passes back.

5. Follow the ureters back until they reach the urinary bladder; dissect away the tissues around the latter and note its form, etc.

6. Open the bladder; find the apertures of entry of the ureters, and pass bristles through them into those tubes. Note the mucous membrane lining the bladder.

7. Remove one kidney from the body and divide it from its outer to near its inner border; turn the two halves apart (still leaving them connected by the tissues at the inner border), and examine the cut surfaces.

8. Note at the inner border (hilus) the dilatation (pelvis) of the ureter; the outer, darker, granular cortical portion of the kidney, and the inner, paler, smoother medullary portion; the papilla formed by a projection of the medullary substance at the hilus, contained in an expansion (calyx) of the pelvis of the ureter.

9. Obtain a fresh sheep's kidney. Divide it by a section made through it from its outer to its inner border. On the cut surfaces the cortex and medulla will be more readily demonstrated than on the rat's kidney. The pyramids of Malpighi will also be easily seen, and the offshoots of the cortex extending between them.