DEVELOPMENT OF ELASMOBRAXCH FISHES. 239 



not contribute mucli to Leydig's previous statements, yet he 

 accepts Leydig's position with reference to the relation of the 

 sympathetic and suprarenal bodies \ 



The general text-books of Histology, KoUiker's work, and 

 Eberth's article in Strieker's Histology, do not give much in- 

 formation on this subject ; but Eberth, without apparently 

 having examined the point, questions the accuracy of Leydig*s 

 statements with reference to the anatomical relations of the 

 sympathetic ganglia and suprarenal bodies. 



The last author who has dealt with this subject is Professor 

 Semper^ He records observations both on the anatomy and 

 development of these organs. His anatomical observations are 

 in the main confirmatory of those of Leydig, but he shews still 

 more clearly than did Leydig the segmental arrangement of 

 the suprarenal bodies. He definitely regards the interrenal 

 and suprarenal bodies as parts of the same system, and states 

 that in many forms they are continuous (p. 228) : 



"Hier freilich gehen sie bei manchen Formen...in einen 

 Korper ueber, welcher zwischen den Enden d. beiden Nieren 

 liegend dicht an der einfachen Caudalvene sitzt." 



With reference to their development he says : " They arise 

 then also completely independently of the kidneys, as isolated 

 segmentally arranged groups of mesoderm cells between the 

 convolutions of the segmental organs ; only anteriorly do they 

 stretch beyond them, and extend quite up to the pericardium." 



To Semper's statements I shall return, but now pass on to 

 my own observations. The paired suprarenal bodies are dealt 

 with first. 



The suprarenal bodies. 



My observations on these bodies in the adult Scyllium have 

 only been made with specimens hardened in chromic acid, and 

 there are many points which deserve a fuller investigation than 

 I have been able to give them. 



^ Stannius' description is not quite intelligible, but appears to point to the 

 existence of a third kind of body connected with the kidney. From my own 

 observations (vide above), I am inclined to regard it as probable that such 

 a tliird body exists. 



'^ Urogenitalsystem d. Plagiostomen. Arb. Zool. Zoot. Inst. z. Wiirzburg, 

 Vol. II. 



