SUPBARENAL BODIES IN PISHES. 47 



posterior bodies than with the anterior. The typical suprarenal structure, he says, is 

 best exhibited in a posterior one. " Externally there is present a fibrous capsule which 

 sends in the septa, imperfectly dividing up the body into a series of alveoli or lobes. 

 Penetrating and following the septa there is a rich capillary network. The parenchyma 

 of the body itself exhibits a well-marked distinction, in the majority of instances, into 

 a cortical and medullary substance. The cortical substance is formed of rather irregular 

 columnar cells, for the most part one row deep, arranged roujid the periphery of the 

 body. The cells measure on an average 'O-S mm. in their longest diameter. The 

 medullary substance is more or less distinctly divided into alveoli, and is formed of 

 irregularly polygonal cells .... &c." 



Balfour mentions also that the protoplasm of both sorts of cells has a yellowish 

 tinge, and that the suprarenals are more or less surrounded by lymphoid tissue. He 

 gives a drawing of these appearances in pi. xviii. fig. 6. As for the connection between 

 the sympathetic ganglia and the suprarenal bodies, he says : — " In the case of one of 

 the posterior bodies, a small ganglion is generally found attached to both ends of the 

 body, and invested in the same sheath ; in addition to this a certain number of 

 ganglion-cells (very conspicuous by their size and other characters) are to be found 

 scattered through the body. In the anterior suprarenal bodies the development of 

 ganglion-cells is very much greater. If a section is taken through the region where 

 the large sympathetic ganglion is attached to the body, one half of the section is 

 composed mainly of sympathetic ganglion-cells and nerve-fibres, and the other of supra- 

 renal tissue, but the former spread in considerable numbers into the latter." At one 

 point {n in pi. xviii. fig. 7) a nerve is shown entering. He states that the ganglion and 

 nerves are so intimately united with the suprarenal body as not to be separable from it. 



Balfour leaves it an open question whether there are cells of an intermediate character 

 between the ganglion cells and the cells of the suprarenal body. Then follow the 

 developmental researches, the general conclusion of which is that the paired " supra- 

 renal" bodies develop as parts of the sympathetic nervous system. 



Passing on to the interrenal body, this author gives a sketch of its general anatomy, 

 and differs from Semper as to the continuity of the two kinds of structure. It will be 

 seen that my own observations agree on this point with Balfour. With regard to the 

 histology of the interrenal, he gives a drawing (pi. xvii. fig. 8), and describes it thus : 

 " It is invested by a fairly thick tunica propria, which sends in septa, dividing it into 

 rather well-marked lobules or alveoli. These are filled with polygonal cells, which 

 form the true parenchyma of the body. These cells are in my hardened specimens not 

 conspicuous by the number of oil-globules. . . . They are rather granular in appear- 

 ance, and are mainly peculiar from the somewhat large size of the nucleus. . . ." 



Balfour notes as difi'erences between the " supra-" and " inter-"renals the distinction 

 into cortex and medulla in the former, and the large size of the nuclei in the cells of 

 the latter. From the developmental standpoint he concludes that the interrenal does 

 not belong to the same system as the suprarenals, and he proceeds to enquire with which 



