74 URINARY ORGANS. 



the apex of the papilla. These tubes are more numerous near 

 the base, in consequence of their successive junction in ap- 

 proaching the apex:* their terminating orifices, on the latter, 

 appear like small pores, from which the urine can be squeezed 

 in little drops. 



In the early part of the course of the cluctus uriniferi, while 

 they are still in the cortical matter, they are wound up in a 

 very serpentine and tortuous* manner, and are distinguished by 

 the name of Cortical Canals, (Ductus Ferrcnii.-f) They com- 

 monly go alone, winding their way in the cortical substance 

 until they reach its most interior face; they then become straight, 

 form the medullary substance, and have the name of the con- 

 duits or uriniferous ducts of Bellini.J 



Some of the calculations on this subject are not a little curious. 

 If was ascertained by Ferrein that in each of the conoidal fas- 

 ciculi (Pyramides Malpighiance) there were, at least seven hun- 

 dred subordinate cones or pyramids, Pyramides Ferrenii; and 

 as the number of conoid'al fasciculi is generally about fifteen, 

 these pyramids would amount to ten thousand five hundred. 

 Again, each of the subordinate pyramids (Pyramides Ferrenii) 

 is composed of many hundred uriniferous tubes, and, by the ob- 

 servations of Eysenhardt,$ each of these tubes consists of twenty 

 smaller ones. 



The kidney receives from the aorta one or more branches, 

 called the renal or emulgent arteries, which divide as they ap- 

 proach the fissure; and having got into the substance of the 

 gland are distributed by innumerable twigs to all parts of it. 

 Some terminate in veins, others in the substance of the organ, 

 and others, again, in the excretory tubes. The veins equal in 

 number the arteries, and are somewhat larger. When both, or 

 even one, of these systems of blood vessels is injected with 

 wax and corroded, its branches are so abundant as to retain the 

 form of the gland. In engaging in the fissure of the kidney, 

 the arterial ramifications are in front, the veins in the middle. 



* Schumlnnsky, Dis. de Struct. Renum, Strasburg-, 1788. 



f A. Ferrein; sur la Structure des reins et du foie. Mem. de Paris, 1749. 



t L. Bellini, de Structura Renum. Florence, 1662. 



$ De Struct. Kenum, Obs. Micros. Berlin, 1818. 



