RENAL SYSTEM OF FISHES. 285 



the tail, the abdominal parietes, and the generative organs has so far 

 the aspect of a ' portal ' or inferent vessel, that a second and larger 

 vein, whose roots take their rise in part from the renal substance, ex- 

 tends from the inner and anterior part of the kidney to convey its 

 blood to the vena cava. The exterior vein is not, however, com- 

 pletely expended in the kidney, but is also continued forwards from 

 the anterior end to join the veins from the anterior abdominal parietes, 

 and sometimes those from the pectoral fins. Whether the blood 

 takes a retrograde course in these towards the kidney, and meets 

 the stream from the hinder commencement of the exterior vein, is 

 luidetermined. In all fishes the kidneys maintain the same relations 

 Avith the cardinal veins that their transitory homologues, the ' Wolf- 

 fian bodies,' do in the embryo of the higher Vertebrates. 



SUPRA-RENAL BODIES. 



Professor Miiller has described two small oval lobulated bodies, 

 situated in advance of the kidneys, close to the portal sinus and 

 near the pericardium, in the Myxinoid Fishes, as the 'glandulse 

 suprarenales. ' * In the typical Osseous Fishes they have been re- 

 cognised as roundish bodies of a light grey colour ; commonly two, 

 rarely three in number ; situated, sometimes near the middle, oftener 

 at the hinder extremities of the kidneys, at or near the entry of the 

 ha3mal canal : sometimes they lie free, sometimes they are imbedded 

 in the renal tissue (Pike, Salmon, Eel) ; but they always possess a 

 proper capsule, and present what seems to be a minutely granular 

 texture, without distinction of cortical and medullary parts. In the 

 yellowish supra-renal bodies of the Sturgeon, the granules are minute 

 spherical cells filled by microscopic nucleated corpuscles. In the 

 Plagiostomes, the supra-renal glands are represented by elongated 

 narrow yellowish bodies, situated behind the kidneys, and sometimes 

 extending behind the dilated ureters. 



* XXI. Angeiologie, 1841, pp. 14 — 17. tab. ii. fig. 2. n. 



