io 3 



LESSON XXIII. 

 KIDNEY, ADRENAL, AND PROSTATE. 



(a) Isolated Tubules of Kidney. 



Pieces from the kidney of a small mammal were macerated for 

 24 hours in a 30 % solution of hydrochloric acid, and washed 

 for % hour in flowing water. Tease very carefuily in gum glycer- 

 ine. 



Different portions of the tubules will be seen in the 

 field. Sketch a Malpighian corpuscle, a convoluted tubule, 

 and a loop of Henle, under low power. 



(b) Longitudinal Section of a Small Kidney. 



The kidney of a young rat or other small mammal was hardened 

 in mercuric chloride, stained in Delafield's haematoxylin, and longi- 

 tudinal sections cut. The sections were fixed to cover glasses and 

 counter-stained in eosin, dehydrated, and cleared in oil of bergamot 

 and xylol. Mount on balsam. 



Study first under low power. In this preparation only 

 one Malpighian pyramid is seen. In the medullary por- 

 tion the tubules have a more or less straight direction, 

 radiating from the apex toward the base of the Malpighian 

 pvramid. In the cortex are observed bundles of straight 

 collecting tubules arranged in the form of pyramids (the 

 pyramids of Ferrein or medullary rays), the bases of which 

 rest on the base of the Malpighian pyramid. Between the 

 medullary rays is found the labyrinth of the kidney, com- 

 posed of Malpighian corpuscles, proximal and distal convo- 

 luted tubules, and spiral and zigzag portions of the urin- 

 iferous tubules. Study the form and structure of the 

 epithelium lining the different portions of the uriniferous 

 tubules under high power. Make an outline sketch of the 

 section as seen under low power. 



