108 THE KIDNEYS, BY J. C. LUDWIG. 



C. Ludwig and Zawarykin. Lastly, the intermediate portion 

 was first recognized to be a constantly present division of the 

 canal by Schweigger-Seidel. 



Our more accurate knowledge of the structure of the walls 

 of the tubuli commences with Henle; he demonstrated the 

 presence of the basement membrane of the cloudy epithelium 

 in the tortuous, and of the transparent in the straight, tubuli ; 

 v. Wittich recognized the want of a cell membrane in the 

 epithelial cells of the tortuous portions of the tubes; Koth 

 discovered that the capsules were composed of endothelial 

 cells; and Steudener, the peculiar form of the epithelial cells 

 in the ascending limb of the loop. 



The greater part of the course of the bloodvessels was easily 

 ascertained as soon as gelatine was employed for the purposes 

 of injection in the place of resin and wax. A few difficulties 

 alone remain to be explained, as in particular the courses of 

 the branches of the arterise interlobulares that enter directly 

 between the glomeruli into the plexus surrounding the urinary 

 tubules ; these vessels were recognized as being commonly 

 present in the kidneys of Mammals by Toynbee, Isaacs, and 

 Schweigger-Seidel; the arteriolse rectse verse were discovered 

 independently of each other by R. McDonnell and Virchow. 



The fibrillated connective tissue of the medulla of the 

 kidney was first described by Goodsir; the peculiar cells of 

 the cortex by Beer and Schweigger-Siedel. 



LITERATURE. 



HUSCHKE, Lehre von den Eingeweiden. Leipzig, 1844. The older 



literature is very fully given in this work. 



TODD and BOWMANN, Physiological Anatomy. London, 1859, Bd. ii. 

 KOLLIKER, Handbuch der Gewebelehre, 1867. 

 GERLACH, MULLER'S Archiv, 1845 und 1848. 

 V. WITTICH, Archiv fur Patholog. Anatomie, 1849. 

 C. E. ISAACS, Journal de la Physiologic, Bd. i., 1858. 

 VIRCHOW, Archiv fur Patholog. Anatomie, Bd. xii. 

 BEER, Die Bindesubstanz der Niere im gesunden und kranken Zus- 



tande. Berlin, 1859. 

 HENLE, Zur Anatomie der Nieren. Abhandlungen der k. Gesellschaft 



der Wissenschaften in Gottingen, Bd. x. 



