SUPEAEENAL BODIES IN FISHES. 71 



outlines can also be perceived. In some cases, as in the Trout, the alveoli are very 

 distinctly marked, and have every appearance of being not closed vesicles, but in 

 communication one with another. 



The essential suprarenal cells I find to be of two kinds. The first are irregular 

 branched cells, most often tending towards a spindle-shape, about 7 Lt-8 u in length, 

 with very large prominent nuclei (PL XIV. figs. 48 & 49). These nuclei are often as 

 large in diameter as the widest part of the cell (i. e., about 3-5 /i) (PI. XIV". fig. 48), 

 and appear to bulge it out at that point. In the nucleus can be seen a number of 

 small dark nucleoli, and often a distinct nuclear network. The protoplasm of these 

 cells is distinctly granular. 



The second kind of cell is usually irregularly triangular, having generally a greatest 

 length of about 6"5 or 7^, with a small dark nucleus not more than 2-5 u. in diameter 

 (PI. XIV. fig. 49). 



These two kinds of cells are readily distinguished, and both are usually present in 

 any given specimen, but in very varying proportions. 



I have doubted whether these appearances might be simply due to treatment or to 

 accidental modes of staining, but I believe they depend in some way on the functional 

 activity (for the suprarenals are not mere embryonic remains), stage of development, or 

 the age of the fish, as their relative occurrence is found to difier very widely even 

 among closely allied species. Thus in Gadus (eglefinus I found nearly all the cells had 

 large round clear nuclei and nuclear figures, while in Merluccius vulgaris the cells 

 appeared almost all to have small dark nuclei ^. This point I hope to have the 

 opportunity of investigating by taking series of specimens of different ages, and after 

 different modes of feeding, starvation, poisoning, &c. At present I must leave their 

 true nature quite an open question. 



There is no disfinction to be made out between cortex and medidla in this order of 

 fishes, or, rather (as appears probable by comparison with other groups of Vertebrates), 

 the suprarenal consists entirely of cortex '. 



I have made careful pi-eparations of the suprarenals of all the species whose gross 

 anatomy is given above, but, as I have said, these do not offer any great variety among 

 themselves. It may, however, be useful to indicate briefly the kind of variation one 

 finds in the different families by a few illustrative extracts from my laboratory note- 

 book. Perhaps one of the most characteristic appearances is found in the MursenidtB. 

 In this family (PI. XIV. figs. 45 & 46) the alveoli are rounded, and contain cells poly- 

 hedral or angular in shape. These are arranged for the most part in a single tier 

 around the circumference of each alveolus, leaving an irregularly-shaped cavity in the 



' I have even found that in one specimen of Midliis hurhatus there was a vast majority of one kind of 

 cell, and in another specimen of the same fish a corresponding preponderance of the other kind. 



^ [Diamare {loc.cit.) has arrived at the same conclusions as myself as regards the homology of the interrenal 

 body in Elasmobranchs with the suprarenal bodies of Teleostei. It foUows that the repriseiiiative of {lie sujjra- 

 renal medulla is absent in Teleosteunjishes. — S. V., 10. 1. 97.] 



