310 



PRACTICAL HISTOLOGY. 



[XXVIII. 



these the interlobular arteries and 

 veins (tig. 299, a), running out- 

 wards in the middle between every 

 two medullary rays (fig. 293). 

 From these are given off on all 

 sides, at short intervals along the 

 course of the vessels, short arteries 

 - the vasa afferentia. Each vas 

 afferens, after a very short course, 

 runs to a Malpighian capsule, and 

 splits up into capillaries to form 

 the glomerulus. 



(b.) If the capsule is cut at the 

 level where the artery enters, the 

 short and narrower efferent vein or 

 vas efferens will be seen coming 

 out at the same pole, and after a 

 similar short course breaking into 

 a network of capillaries, which sur- 

 rounds the tubules of the cortex. 

 Around the convoluted tubules the 

 meshes of the network are some- 

 what polygonal, but in the medul- 

 lary rays in the cortex they are 

 more elongated. 



(c.) From this capillary network 

 arise' short veins, which join the 

 interlobular veins (fig. 299). Quite 

 at the upper end of the inter- 

 lobular artery a few branches are 

 given off, which end directly in 

 this capillary network without the 

 intervention of glomeruli. Under 

 the capsule the small veins are 

 arranged in a stellate manner, con- 

 stituting the venae stellatte (fig. 

 299, S). 



(d.) Passing again to the "line 

 of vascular supply," the short 

 vessels which break up into leashes 

 Fia. 299. Blood-Vessels of the Kidney. O r bundles of small blood-vessels 



med^nal'^Inteflobufar^rtefy ; i. (fig- 299, r), the Vasa recta (arteriffi 

 Vas afferens;. 2 Vas efferens; r e. Tec fa venaS rectae), which rim be- 

 Vasa recta; FF. Interlobular vein ; 



s. Origin of a stellate vein ; i, i. BOW- twecn the medullary rays into the 



man's capsule and glomerulus; P. ^n.lnWi WI-.OT-G fViov fnrrn nn 



Apex of papilla ; c. Capsule of kid- medulla, where they lorm an 

 ney; e. Vasa recta from lowest vas elongated capillary meshwork be- 



efterens. J 



