300 S. Vincent, 



venous blood from the Renal Portal vein. But there are no capsular 

 arteries direct from the aorta; whatever arterial blood the bodies 

 receive, they get indirectly from the arterioles distributed on the kidney. 

 The tributaries of the Posterior Vena Cava, bringing impure blood 

 from the kidney, run for some distance longitudinally along the anterior 

 surface of the organs and around this part of their course the suprarenal 

 substance is collected. There are some three or four of these branches 

 on each side. It would almost appear as if the suprarenal had had 

 its exact location on the surface of the kidney determined by these 

 veins, for the discontinuity above mentioned corresponds fairly well 

 with the occurrence of the venous tributaries. In some cases the 

 suprarenal capsule appears to be little more than a kind of glandular 

 wall to the vein, and this explains the interesting fact first noticed 

 by Gruby [50] that when the blood-vessels are distended, the suprarenals 

 become less distinctly visible. 



The suprarenal body forms a distinct bulging on the ventral surface 

 of the kidney as shewn in transverse section (PI. XVII. fig. 11). It is 

 enclosed in the capsule of the kidney and there is no sheath or septum 

 of any kind between the cell-columns and masses of the former and the 

 tubules and malpighian bodies of the latter. The line of demarcation 

 between the two structures is however fairly definite, although there 

 is no connective-tissue boundary. 



The gland is seen at once to consist of two distinct kinds of 

 structure. The greater part is made up of columns of cells which 

 are of varying size and shape and interlace in all directions (PI. XVII. 

 fig. 11 and PI. XVI. fig. 12). The constituent cells vary somewhat in 

 shape but are mostly elongated or columnar, and contain a large round 

 nucleus with nucleoli. This substance is the "cortical", which is homo- 

 logous with the interrenal body of Elasmobranchs, the known supra- 

 renal bodies ("corpuscles of Stannius") of Teleosts, and the cortical 

 substance of the suprarenal bodies of Reptilia, Aves, and Mammalia. 



But in addition to the above-described structure, we get masses 

 of a diâ"erent kind of cell (me., PL XVII. fig. 11 and PI. XVI. fig. 12). 

 These are to some extent irregularly distributed, but there is usually 

 a more or less continuous tract of them along the dorsal border of 



