306 S. Vincent, 



the organ, just within the capsule, with points of irruption here and 

 there, whence start the branching and interlacing cords which are found 

 throughout the organ. 



The medullary masses in the outer portion of the suprarenal body 

 are always more abundant in the neighbourhood of the nerve-ganglia. 



The cortical substance (co., PL XVin. fig. 14) has the form of 

 gland vesicles of very varying size and shape. The cells (e. c) form 

 a regular row of columnar shape, constituting a peripheral layer round 

 each alveolus. In the small peripheral cylinders, there is often only 

 one layer, which bounds a distinct, round or oval, lumen. But in 

 most cases the structure is that of solid masses of polyhedral cells 

 surrounded by a layer of columnar ones and having no lumen (PI. XVIII. 

 fig. 14). The cells are finely granular and contain in a fresh state 

 numerous fat-globules. 



The medullary cell-columns (PL XVIIL fig. 14 me) are smaller than 

 the cortical, and shew no regular glandular arrangement of the cells. 

 These are considerably larger than the cortical cells and more irregular 

 in shape. After treatment with hardening fluids containing bichromate 

 of potassium, they shew a tendency to separate from each other, 

 leaving clear spaces between them. The most distinct feature of 

 these cells is the brown pigmentation which occurs after such treat- 

 ment. This is sometimes uniform throughout the cell protoplasm, some- 

 times in the form of distinct granules. Henle [54] first called attention 

 to this universal mode of distinguishing medulla from cortex, But as 

 Rabl [91] points out, and as I have already indicated for lower forms, 

 other modes of staining show a marked distinction between the two 

 structures. Thus with haematoxylin the cell -protoplasm stains almost 

 as deeply as the nucleus. The same applies to several other nuclear 

 stains. This indicates that the cell -protoplasm of the medullary sub- 

 stance approximates either in chemical or physical properties to nuclear 

 material. At the same time, the bichromate test is extremely useful 

 and quite unique, as no glandular tissue except the medulla of the 

 suprarenal capsule gives the same reaction. The medullary cells con- 

 tain no fat. 



Rabl (loc. cit.) has applied the very appropriate names "Haupt- 



