518 SUPRA-RENAL CAPSULES. [CHAP. XXXV. 



a fibrous appearance. The medullary substance is of a paler color, 

 unless the vessels are injected with blood, and of a somewhat softer 

 consistence. If the gland be not perfectly fresh, a cavity is usually 

 seen in the interior, which results from the breaking down of 

 the medullary tissue. 



The cortex is divided into a series of compartments or tubes by 

 septa of fibrous tissue prolonged inwards from the capsule of the 

 organ. These spaces extend through the entire thickness of this 

 part of the body, and pass from the surface vertically inwards. 

 They contain numerous oval or spherical bodies, varying consider- 

 ably in length. These have been looked upon by Ecker as gland- 

 follicles, but Kolliker considers them merely as aggregations of 

 cells not invested with a distinct membrane, or enclosed in a larger 

 cell. They are separated from each other by meshes of areolar 

 tissue, the fibres of which often appear to be connected with the 

 surface of the mass. In the outer part of the cortex separate cells, 

 filled with pigment granules, are usually to be met with ; but in 

 the inner portion, round or oval vesicles are found, which are filled 

 with oil globules. 



The medullary substance is composed of a network of areolar 

 tissue which is prolonged from the cortex, and contains numerous 

 vessels, in the meshes of which are found many cells, some of which 

 contain fat or granular pigmentary matter. A distinct nucleus and 

 commonly a nucleolus are seen, and often the cells have many an- 

 gular processes, or are much branched ; indeed, these cells present 

 an appearance much resembling that of the nerve vesicle. 



Besides the fibrous, vascular, and cellular elements just described, 

 the medullary portion of the supra-renal bodies is very largely 

 supplied with nerve fibres derived from the semilunar ganglia 

 and solar plexus, with a few fibres also from the pneumo-gastric, 

 and from the phrenic. The nerves appear to perforate the cortical 

 substance in several places, pass through this, and enter the me- 

 dullary, where they form a plexus amongst the fibrous tissue. The 

 mode of their termination has not been made out. 



The function of these peculiar bodies is entirely unknown. 

 From the great dissimilarity of structure observed in the cortical 

 and medullary portions of the organs, it is probable that each per- 

 forms a distinct and separate office. In the present state of oui 

 knowledge we may continue to classify the former with the ductless 

 or vascular glands, but, from the existence of cells much resembling 

 nerve vesicles, and an abundant plexus of nerve fibres, it ap- 

 pears more correct to regard the latter as connected in some man- 



