ORIGIN AND COURSE OF THE TUBES. 



935 



have already been noticed in its application to the liver. For the kidney 

 Chrzonszczewsky made use of the carminate of ammonia, which is freely 

 eliminated with the urine. In order to obtain a full colouring of the 

 blood-vessels, first the renal veins, and afterwards the arteries, are tied 

 soon after a certain portion of the coloured fluid has been introduced 

 into the jugular vein of the living animal. To obtain a coloured injection 

 of the uriniferous tubes, the animal is allowed to live for about an hour 

 after the introduction of the carmine liquid, and then the ureters are 

 tied, while the renal blood-vessels are carefully washed out with a weak 

 solution of common salt ; and, to preserve the specimens from after infiltra- 

 tion of the colour, they are immersed in absolute alcohol acidulated with 

 glacial acetic acid. 



Fig. 657. 



Fig. 656. 



Fig. 656. TRANSVERSE SECTION OF THE MEDULLARY SUBSTANCE OF THE PIG'S 

 KIDNEY (from Chrzonszczewsky). 



The drawing represents a small portion of the kidney of an animal into which colouring 

 matter had been infused during life so as to fill the blood-vessels, by which means the 

 distinction between them and the uriniferous tubes both larger and smaller is established, 

 as well as by the different character of the lining epithelium ; the section is made near the 

 papilla; TB, the larger uriniferous tubes or tubes of Bellini ; TF, the smaller uriniferous 

 tubes or looped tubes of Henle, named by Chrzonszczewsky tubes of Ferrein ; VR, the 

 vasa recta or larger blood-vessels; c, the small vessels and capillaries; s, the stroma. 



Fig. 657. LARGER AND SMALLER URINIFEROUS TUBES FROM THE MEDULLARY 

 SUBSTANCE OF THE PIG'S KIDNEY (from Chrzonszczewsky). 



1, 1, two of the larger tubes, connected by a transverse tube at 2, and presenting a 

 looped arrangement at 3 ; from this place two smaller uriniferous tubes, 4, 4, are seen 

 taking their origin, as well as at the other places, 5, 5. 



Blood-vessels. The kidneys are highly vascular, and receive their blood 

 from the right and left renal arteries (p. 414), which are very large in pro- 

 portion to the size of the organs they supply. Each renal artery divides 

 into four or five branches, which, passing in at the hilus, between the vein 



