242 ELEMENTS OF HISTOLOGY, tchap. xxx. 



arrangement. The capillaries of the whole cortex 

 form one continuous network. 



316. The veins which take up the blood from this 

 network are arranged in this manner : There are 

 formed venous vessels underneath the external 

 capsule, taking up like rays on all sides, minute 

 radicles connected with the capillaries of the most 

 peripheral part of the cortex. These are the vence 

 stellatoe; they pass into the labyrinth of the 

 cortex, where they follow a vertical course in 

 company with the interlobular arteries. On the 

 way they communicate with the capillaries of the 

 labyrinth, and ultimately open into the large 

 venous branches situated between cortex and boun- 

 dary layer. 



317. (2) In the medulla. From the large arterial 

 trunks short branches come off, which enter the 

 boundary layer, and there split up into a bundle 

 of minute arterioles, which pass in a straight direc- 

 tion vertically through the boundary layer into the 

 papillary portion. These are the arterice rectce 

 (Fig. 136). The number of vessels of each bundle 

 is at the outset increased by the efferent vessel of 

 the Malpighian corpuscles nearest to the boundary 

 layer. 



' On their way through the boundary layer, and 

 through the papillary portion of the medulla, 

 these arterioles give off the capillary network for 

 the urinary tubules of these parts, the network, 

 for obvious reasons, possessing an elongated arrange- 

 ment. 



From this network originate everywhere minute 

 veins, which on their way towards the cortical margin 

 increase in size and number ; they form also bundles 

 of straight vessels vence rectce and ultimately enter 

 the venous trunks situated between the boundary 

 layer and cortex. 



