468 DEVELOPMENT OF ELASMOBRANCH FISHES. 



developed from the mesoblast ; while my researches on the 

 suprarenal bodies confirm the brilliant investigations of Leydig, 

 shewing that they are formed out of the sympathetic ganglia. 



The most important investigations on these bodies have been 

 made by Leydig 1 . In his first researches, Rochen u. Haie, pp. 

 71, 72, he gives an account of the position and histology of what 

 is probably my interrenal body 2 . 



The position and relations of the interrenal body vary some- 

 what according to Leydig in different cases. He makes the fol- 

 lowing statement about its histology. " Fat molecules form the 

 chief mass of the body, which causes its white, or ochre-yellow 

 colour, and one finds freely embedded in them clear vesicular 

 nuclei." He then proceeds to state that this structure is totally 

 dissimilar to that of the Mammalian suprarenal body, and gives 

 it as his opinion that it is not the same body as this. In his 

 later researches 3 he abandons this opinion, and adopts the view 

 that the interrenal body is part of the same system as the supra- 

 renal bodies to be subsequently spoken of. Leydig describes 

 the suprarenal bodies as paired bodies segmentally arranged 

 along the ventral side of the spinal column situated on the 

 successive arteriae axillares, and in close connection with one or 

 more sympathetic ganglia. He finds them formed of lobes, 

 consisting of closed vesicles full of nuclei and cells. Numerous 

 nerve-fibres are also described as present. With reference to the 

 real meaning of these bodies he expresses a distinct view. He 

 says 4 , "As the pituitary body is an integral part of the brain, so 

 are the suprarenal bodies part of the sympathetic system." He 

 re-affirms with still greater emphasis the same view in his FiscJic 

 n. Rcptilien. Though these views have not obtained much 



1 Rochen und Haie and Untersuchung. ii. Fische ti. Reptilien. 



2 I do not feel sure that Leydig's unpaired suprarenal body is really my interrenal 

 body, or at any rate it alone. The point could no doubt easily be settled with fresh 

 specimens, but these I unfortunately cannot at present obtain. My doubts rest partly 

 on the fact that, in addition to my interrenal body, other peculiar masses of tissue 

 (which may be called lymphoid in lieu of a better name) are certainly present around 

 some of the larger vessels of the kidneys which are not identical in structure and 

 development with my interrenal body, and partly that Stannius' statements (to be 

 alluded to directly) rather indicate the existence of a second unpaired body in con- 

 nection with the kidneys, though I do not fully understand his descriptions. 



a Fische 11. Reptilien, p. 1 4. 

 4 Rochen u. I fate, p. 18. 



