The Comparative Histology of the Suprarenal Capsules. 293 



the cells are more polyhedral or irregular. Like the alveoli, they vary 

 somewhat in size; their average diameter is about 20 f.i. The nuclei 

 (n) are deeply stained and somewhat irregular in shape, having a 

 diameter of 3 — 6 fi. The protoplasm is very finely granular as a 

 rule, occasionally more coarsely granular. There are small nerve- 

 ganglia in connection with some of the bodies." 



It was concluded: — "I have no doubt, from the above structure, 

 that these bodies are the representatives of the suprarenal gland in 

 Ganoids, and in my opinion they correspond to the cortical portion in 

 higher Vertebrata". I have not had the opportunity of putting the 

 matter to the physiological test in the case of the Ganoids. 



5. Teleostei. 



I have found suprarenal bodies in all fresh specimens examined. 

 They are usually paired, round or oval, pale pink bodies, placed on 

 the spinal or ventral surface of the kidney. They are near the 

 posterior extremity of the renal mass, and are either free on its 

 surface or more or less imbedded in its substance. 



Histologically examined, the organs are found to be surrounded by a 

 fibrous capsule which varies in the species examined from about 4 to 

 70 f.1 in thickness. Externally to this capsule the intertubular adenoid 

 tissue of the kidney is more abundant than in the other parts of the 

 renal mass. The capsule is always thicker where the suprarenal 

 adjoins the kidney substance, because here we have a double layer 

 consisting of the capsule of the suprarenal body fused with the proper 

 capsule of the kidney. The suprarenal glands are thus quite distinct 

 and separate from the kidney substance. They are in fact simply 

 placed in depressions upon the surface of the kidney. 



The fibrous capsule sends in trabeculae, which divide and subdivide 

 in the interior of the gland, and divide this up into vesicles or alveoli, 

 which bear a striking resemblance to those of the interrenal body of 

 Elasmobranchs. It is difficult to determine from sections the precise 

 form of these gland vesicles in the different species, but it seems that 

 in some cases they are tubular structures (see PI. XVI. fig. 7 and 

 PI. XVn. figs. 8 and 9), while in others they closely approximate 



