77 



whoro tlio latter vessol leaves the kidney. They are 

 yellow or pink in colour, and contrast strongly with the 

 pigmented kidney. In a specimen of about 22 inches in 

 total body length, the largest measured 5'5mni. in longest 

 diameter. They lie in little cavities in the kidney tissue, 

 but project slightly al)ove the surface of the latter, in the 

 capsule of which they are enclosed. Their blood supply 

 is from a twig of the common genital arterv, and their 

 minute structure is somewhat similar to that of a 

 lymphatic gland. The capsule is continuous with a system 

 of fibrous trabeculse traversing the whole organ. These 

 trabecule form the coarser bars of a reticulum the meshes 

 of which are crowded Avith small cells which mav be 

 described as lymphoid in appearance. According to 

 Vincent they are secreting glands affecting the composi- 

 tion of the blood b}^ furnishing an internal secretion. 



Until comparatively recent times it was supposed that 

 the suprarenal bodies were absent in Teleostean llshes.f 

 It has, however, been shewn by Vincent* that they are 

 probably universally present. As is well known, the 

 suprarenals of mammalia consist of two ni(nphologically 

 distinct portions — the cortex and medulla. The latter has 

 been stated to have been derived from certain of the sym- 

 pathetic ganglia, and concerning the former an interesting 

 suggestion has been made by Weldon and Grosglik. It is 

 certain, however, that the most important relations of the 

 suprarcMial bodies are with the vasculai', not the nervous 

 system. 



4. — Thk Uf.nal Organs. 



The Kidney (tigs. 20 and 21) lies along the whole 

 dorsal, and ])art of the posterior wall of the body cavity, 



I ('ii. Wchlnii -Head Kidiicv in iKlfllostoiua — SLmlif- Mc.i|ili. I, ah. 



L'aiubridno, vi>l. ii., \>t. 1, 1884. 



* Cniitribulidiis to Anatomy and Jlislology of the SuiJiarcnal Capsnlcs, 



'i'rans. Zool. Soc, London, vol. xiv., pp. 41-^4, lS'.)t;-«. 



