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STUDENTS HISTOLOGY 



PRACTICAL DEMONSTRATION 



The human kidney is rarely found in a perfectly normal condition. The 

 demonstration can be made from the kidney of the pig, except as regards 

 certain features. The medullary pyramids do not exist in the domestic ani- 

 mals, and the parenchyma presents very essential differences from the cells of 

 the human kidney. Still, very much can be learned from the organ of the pig, 

 dog, or rabbit. The tissue should be divided so as to permit sections to be 

 made parallel with the medulla, and to include both it and the cortex. The 

 hardening is best by Miiller's fluid. Small pieces hardened quickly in strong 

 alcohol, however, stain very finely with heematoxylin and eosin. Sections of 

 .kidneys the blood-vessels of which have been injected should also be studied. 



,Fio. 118. SECTION OF HUMAN KIDNEY, CUT PARALLEL TO THE PYRAMIDS OF FERREIN. 

 SHOWING THE CORTEX AND PART OF A MALPIGHIAN PYRAMID (X 30). 



A, A. Capsule of kidney. 



B, B. Pyramids of Ferrein. 



C, C. Cortical labyrinths. 



D, D. Malpighian bodies. Many of the glomeruli drop out in the course of preparation, and 

 such empty capsules of Bowman appear as light circular spots. 



E, E. Interlobular arteries. 



F, F. Boundary region. 



G, G. Transverse sections of vessels of the arcades. 

 H. Base of a Malpighian pyramid. 



