Chap, xxx.] KIDNEY, URETER, AND BLADDER. 229 



corpuscles, whence it travels into the labyrinth of 

 minute spaces in the honeycombed pulp matrix ; 

 thence it passes into the venous sinuses, and finally 

 into the venous trunks. The current of blood on its 

 passage through the pulp tissue becomes, therefore, 

 greatly retarded. Under 'these conditions numerous 

 red blood-corpuscles appear to be taken up by the 

 cells of the pulp, some of which contain several 

 in their interior. In these corpuscles the blood-discs 

 become gradually broken up, so that, finally, only 

 granules and small clumps of blood-pigment are left 

 in them. The presence of blood-pigment in the cor- 

 puscles of the pulp is explained in this way ; and it is 

 therefore said that the pulp tissue is a destroyer of 

 red blood-corpuscles. 



The pulp tissue is most probably the birthplace of 

 colourless blood-corpuscles ; and according to Bizzozero 

 and Salvioli it is also the birthplace of red blood- 

 corpuscles. 



The lymphatics form plexuses in the capsule 

 (Tomsa, Kyber). These are continuous with the plexus 

 of lymphatics of the trabeculse j and these again with 

 the plexus of lymphatics in the adventitia of the 

 arterial trunks. 



Non-medullated nerve-Jlbres have been traced along 

 the arterial branches. 



CHAPTER XXX. 



THE KIDNEY, URETER, AND BLADDER. 



300. A. The framework. 



The kidney possesses a thin investing capsule com- 

 posed of fibrous tissue, more or less of a lamellar 

 arrangement. Bundles of fibrous tissue pass with 



