SUPEAKENAL BODIES IN FISHES. 65 



Paired "Supeaeenal" Bodies. — With regard to the segmentally-arranged bodies, there 

 is not a great deal new to be said. But it is certain that in all cases the structure is very 

 different from that which Balfour described and depicted. Chevrel explains Balfour's 

 appearances as due to the action of reagents, and I am satisfied, from the examination 

 of many individuals and many species with various modes of preparation, that there is 

 never any such arrangement of a cortex of columnar and a medulla of polyhedral cells 

 {PI. XIII. figs. 41 & 42). 



The structure of these bodies is far from easy to describe, and this I find, notwith- 

 standing that my material was perfectly fresh and my preparations mostly very satis- 

 factory. The organs are surrounded with a tolerably firm fibrous capsule of a thickness 

 about 4-7 fi (PI. XIII. fig. 41, c), which sends in septa (s.), which in some parts are 

 distributed almost as regularly as in a Mammalian lymphatic gland. These septa 

 rapidly break up into an irregular fibrous meshwork which is distributed throughout 

 the body (PI. XIII. fig. 41, str.). 



The parenchyma of these bodies is not arranged in any definite acini or alveoli, thus 

 marking them off distinctly from the suprarenals in Teleosts, Ganoids, and the interrenal 

 lody in Elasmoiranchs (q. v.) and indeed from suprarenal capsules in other Vertebrata. 



There are, as a rule, no definite cell-outlines to be made out, and the main part of 

 the parenchyma appears to consist of an irregular or wavy fibrous stroma (PL XIII. 

 fig. 41, str.), with protoplasm (pr.) and scattered nuclei of round or ov&l shape (n.). 

 The protoplasm is often granular, sometimes finely, sometimes coarsely. The nuclei 

 are of difl'erent characters, sometimes showing nuclear figures, at other times devoid of 

 them, sometimes large and faintly stained, sometimes small and darkly stained. They 

 vary in diameter from 5 to 9 |U. However unsatisfactory this may seem, it is all that 

 can be ascertained, and it is difficult to imagine how former observers such as Leydig 

 and Balfour could have described them as having definite lobules and cell-outlines. 



But there are definite cells in some parts (PI. XIII. fig. 42, ]).c.) quite apart from 

 the easily recognizable nerve-ganglion cells. They have, so far as I know, not been 

 previously described. They are mostly triangular or multipolar in shape (PL XIII. 

 fig. 42, ;p.c.) and of a uniform sepia-brown tint, and they contain large, very darkly 

 stained, round nuclei. It is difficult to state their size, as their shape is so irregular ; 

 they vary, however, in their greatest lengths from 10-30 fj. ; the nucleus is usually 

 about 6-8 ju in diameter. These cells are found particularly in the more central 

 parts of the anterior paired bodies, but their distribution is irregular. The brown 

 coloration of these cells is possibly due to the Miiller's fluid in which the material 

 was hardened. But, even if this be the case, the appearances indicate a difference in 

 chemical reaction, and therefore in physiological import. These cells appear in some 

 places to communicate together by their processes, but whether this communication is 

 real or apparent I cannot be absolutely certain. Is it possible that these cells have 

 anything to do with nerve-cells ? 



VOL. XIV. — PAET III. No. 4, — A^ml, 1897. K 



