STRUCTUEE OF THE KIDNEYS. 



409 



meter, but sometimes only -^^^th. or ^-^oth of an inch. They consist 

 each of a membranous capsule, containing a tuft of blood-vessels. The 

 yascular tuft or glomerulus is formed by a small afferent artery (fig. 

 292,/; fig. 293, V, v'), breaking up at once into a number of minute 

 branches, which form convoluted loops, and are re-united in a single, 

 somewhat smaller efferent vessel (fig. 292,^ ; fig, 293, c, e)), placed close 



Fig. 292, 



Fig. 293. 



,€^^. 



Fig. 292. — Semidiagrammatic He- 

 presentation OF A MaLPIGHMN 

 Body in its relation to the 

 UriniferousTube (fromKolliker). 

 300 Diameters. 



ff, capsule of the Malpighiau body 

 continuous with b, the membrana 

 propria of the coiled uriniferous tube ; 



c, epithelium of the Malpighian body; 



d, epithelium of the uriniferous 

 tube ; e, detached epithelium ; /, 

 afferent vessel ; g, efferent vessel ; 

 /(, convoluted vessels of the glome- 

 rulus. 



.7=^ 



Fig. 293. — Malpighian Corpuscle from the Rabbit's Kidney : nitrate of silver 

 preparation. Highly magnified (Ludwig). 



V, vas afferens, showing its epithelioid lining : at v', the 'transverse muscular fibres 

 are also seen ; c, vas efferens ; a, a', basement membrane of capsule with ejjithelioid 

 markings, passing at h into that of the commencing uniferous tubule. 



to the afferent : the further history of the afferent and efferent vessels 

 will be given later. The capsule, by which the glomerulus is enclosed, 

 is formed of a basement membrane lined by flattened epithelium (fig. 

 294, d). It receives the two vessels at one part ; and at another is 

 continued as already stated into a convoluted uriniferous tubule, as was 

 first pointed out by Bowman (fig, 292), The epithelium lining the 

 capsule is reflected over the glomerus, the cells becoming thicker and 

 less flattened (fig. 294, c) ; it is doubtful whether in the adult they in 

 all cases form a continuous layer over the vascular tuft, but in the 

 foetus it is not difficult to recognise both layers. Sometimes the tuft 

 is divided into two or or three bunches of vessels, in which case the 



