802 THE SUPRARENAL CAPSULES. [BOOK n. 



A large number of nerves, consisting partly of medullated, but 

 chiefly of non-medullated fibres from the solar plexus, the renal 

 plexus, the phrenic nerve and the vagus, pass into the suprarenal 

 body at the hilus and at other parts of the surface. Some, forming 

 plexuses coarse and fine, end in the cortex in connection on the 

 one hand with the blood vessels, and on the other hand with the 

 columns and groups of cells. The greater number however are 

 destined for the medulla, where they form close set plexuses 

 between the groups of cells and appear to end largely by fine 

 networks around the cells. A number of distinct nerve cells are 

 seen in connection with the bars of the plexuses. 



The lymphatics are fairly numerous and form plexuses in the 

 capsule and in the connective tissue of the frame-work ; it is stated 

 that the lymphatic vessels surrounding the groups of cells in the 

 cortex communicate with spaces between the cells. 



498. Besides the ordinary proteid and other chemical 

 constituents, the suprarenal body contains some substance or 

 substances, possessing striking colour reactions, giving a dark blue 

 or dark green colour with ferric chloride, and a carmine red tint 

 with various oxidising agents. This substance (whose nature is 

 not exactly known, and which is confined to or most abundant in 

 the medulla) is not soluble in the ordinary solvents of pigments, 

 such as alcohol, ether, chloroform &c., but is readily soluble in dilute 

 acids. 



Among the extractives, hippuric, or benzoic acid, and tauro- 

 cholic acid or taurin have been found, but it is not certain that 

 these are normal constituents. 



499. Some of the histological features of the suprarenal 

 bodies, namely the groups of cells and their abundant blood supply, 

 suggest on the one hand that important metabolic processes take 

 place in them, some of which are probably connected with the 

 history of the pigments of the body at large. On the other hand 

 the unusually large nerve supply, and the derivation of part of the 

 body from the sympathetic ganglia, suggest peculiar nervous con- 

 nections. And the organ has often served as a starting point for 

 speculations in these two directions ; but our exact knowledge 

 concerning them is limited. Removal of both suprarenal bodies 

 produces symptoms which so far resemble those following the 

 removal of the whole of the thyroid in that they are symptoms of 

 disorder and end in death. But the symptoms are different in 

 character, seeming to bear more especially on the skeletal muscles, 

 and are more acute, so that death is speedy, often taking place in 

 one or two days. The removal of one suprarenal alone appears to 

 have no marked effect ; and the symptoms following removal of 

 both are said to be mitigated by the injection of an extract 

 prepared from the fresh organ ; but as in the case of the thyroid, 

 the chain of events through which the removal of the organ 

 produces the several symptoms has not yet been worked out. 



