290 



THE URINE. 



renal artery and vein c , " which are excessively large in propor- 

 tion to them ; and imbedded in sebaceous fat. 



" They are enveloped in a membrane of their own, which is 

 beautifully vascular ; and each, especially during infancy, con- 

 sists of eight, or rather more, smaller kidneys, each of which 

 again consists, as Ferrein asserted, of seventy or eighty fleshy 

 radii, denominated by him pyramides albidae. 



" A kidney, if divided horizontally, presents two substances ; 

 the exterior, called cortex ; the interior, medulla.** 



* Each abounds in blood-vessels ; but the cortical portion has 

 likewise very minute colourless tubes which " are the origins of 

 the uriniferous ducts*; the medullary part contains these ducts. 

 The blood-vessels are distributed in rather a reticulated manner 

 among the tubes, with which they have no communication of canal. 

 Small round hollow bodies are also seen, containing blood, and 

 connected with the blood-vessels, but with them only. f 



" These tubes arise, in the manner formerly described" in regard 

 to the bile ducts, from minute blind extremities, not dilated, but 



nearly of the same diameter as the rest of the canal, and " formed 



in the cortical part ; of which 



they constitute the greatest 



portion." They preserve an 



angular course in the cortica 



part ; but in the medullary, 



where they are called the Bel- f C) P a P illae - 



linian tubes, they run straight. f /J^lj HB ^wf""' 3 ' 



The cortical part " principally J|| MBKiBHSi /' ureter. 



consists of them; and, after 



they have coalesced into fewer 



trunks, their mouths perforate, 



in the form of so many cones, 



c " Eustachius, tabulae, i. v., which belong to his classical work De renibus 

 published with this great man's other Opusc. anatom. Venet. 1564. 4to. Also 

 tab. xii." 



d " C. W. Eysenhardt, De structura renum Observationes Microscopices. Berol. 

 1818. 4to." 



e " These appear to have imposed upon Ferrein as a new description of vessels 

 which he called neuro-lymphatics, or white tubes, and of which he imagined the 

 whole parenchyma of the viscera to be composed. He affirmed that they were of 

 such tenuity, that their length in each kidney of an adult man was equal to 1000 

 orgyiae (60,000 feet) or five leagues." 



f Mueller, De glandularum sccementium, $c. p. 102. 



