122 PRACTICAL HISTOLOGY. 



squamous epithelium. Profile views of the nuclei of the 

 epithelial cells will probably be obtained. The squamous 

 epithelium of the capsule is reflected over the capillaries 

 of the glomerulus, but it is scarcely possible to see this, 

 save in the young child. Examine the epithelium of the 

 convoluted and that of the straight tubules. 



210. Mount an unstained V. S. Malpighian pyramid, 

 and compare it with the above. Especially look at the ap- 

 pearance of the unstained epithelium of the tubules. 



211. Examine (H.) V. S. Malpighian pyramid of rabbit's 

 kidney hardened in chromic acid ( 207, d}. The columnar 

 epithelium of the larger straight tubules can be remarkably 

 well seen near the apex of the pyramid. The epithelium 

 of the convoluted tubules is not so good as in the Miiller's 

 fluid kidney. The divisions of the straight tubules may be 

 seen ; and the small looped tubules of Henle may often be 

 recognised. 



212. (H.) Scrape the cut surface of the cortex of fresh 

 kidney of sheep to get isolated glomeruli, epithelium, and 

 basement membranes. Examine in salt solution, then add 

 acetic acid and notice its effect on the glomerulus. It 

 renders the capillary walls extremely transparent, and re- 

 veals their nuclei. 



213. (H.) T. S. Malpighian pyramid of Miiller's fluid 

 kidney near its apex. Examine and preserve in Farrants' 

 solution or in glycerine. (The section is best made from a 

 frozen kidney, but may also be made with a Valentin's knife.) 

 Study the T. S. tubules, and the matrix of connective tissue 

 between them. The connective tissue is evident in the 

 medullary part of the kidney, but it is very scanty in the 

 cortex. 



214. V. S. Malpighian pyramid of injected kidney. 

 Mount in dammar, and examine. 



(L. and H.) See the interlobular arteries in the cortex ; 

 the glomerulus, each with its afferent vessel derived from 

 the interlobular artery and the efferent vessel breaking up 

 into a second set of capillaries around the convoluted 

 tubules. See also the vasa recta between the pyramids of 

 Ferrein. 



