744 THE UEINAEY TRACT. 



nerve-fiber, though this connection is indirect through the inter- 

 epithelial filaments of living matter (the so-called thorns). It 

 could not be demonstrated that the nerve-fibrillae penetrate the 

 interior of the epithelia. 



RESEARCHES IN THE MINUTE ANATOMY OF THE EPITHELIA OF THE 

 KIDNEY. BY HENRY B. MILLARD, A. M., M. D.* 



R. Heidenhain t was the first to call attention to the presence of a peculiar 

 rod-like or bacillated structure existing in the uriniferous tubules. He found 

 this structure in convoluted tubules, in the ascending portions of the looped 



N D 



FIG. 335. PYRAMIDAL SUBSTANCE OF THE KIDNEY OF A DOG. 

 SAGITTAL SECTION. BLOOD-VESSELS INJECTED. 



N, narrow or loop-tubule ; ND, descending branch of narrow tubule ; 6', straight collecting 

 tubule ; V, vasa recta. Magnified 500 diameters. 



tubules, and in the intercalated tubules of the kidneys of mammals. Accord- 

 ing to his view, the rodlets (Stabchen) are plainly visible in the outer portions 

 of the epithelia that is, in those portions lying next the connective tissue, 

 and he sometimes saw in torn epithelia the rods isolated. The same observer! 

 also first demonstrated with accuracy that the secretion of the salts is per- 

 formed only in the tubules, in accordance with the views maintained by Bow- 

 man. Charcot deduces from the experiments of Heidenhain with indigo-blue 



* Abstract of the author's essay. The New York Medical Journal, June, 1882. 



t "Mikrosk. Beitrage zur Anat. und Physiologie der Nieren." Max Schultze's "Arch. f. 

 mikr. Anat.," 10 Bd., 1874. 



t " Verauche ttber den Vorgang der Haruabsonderung." Pfliiger's " Archiv," 9 Bd., 1874. 

 page 1. 



% "Charcot on Bright's disease," translated by Millard, New-York, 1878, page 23. 



