88 ATROPHY, DEGENERATION, PIGMENTATION, AND NECROSIS. 



action for iron, 1 while certain further decomposition products, IKCHKI- 

 toidin, for example, in amorphous or crystalline form, do not. Eed blood 

 corpuscles may be taken up by various forms of phagocytes, and within 

 these cells the decomposition of the haemoglobin may lead to their pig- 

 mentation. On the other hand, haemolysis may take place in the circu- 

 lating blood in many forms of poisoning, in acute infections, notably in 

 malaria, in pernicious anaemia, in various cachexiae, etc. The haemo- 

 globin thus set free in the body fluids may be eliminated or it may un- 

 dergo decomposition, and its derivatives may be deposited in the tissues 

 as pigment granules. 



FIG. 25. H^MATOGENOUS PIGMENT IN CONNECTIVE-TISSUE CELLS. 



A condition called hcemochromatosis has been described, in which a 

 brown pigment probably derived from the haemoglobin of the blood is 

 deposited in various tissues of the body. The organs in this condition 

 may appear notably pigmented on gross examination. The pigment 

 particles which are found in the epithelial cells of glands, especially of 

 the liver and pancreas, contain iron ; while an iron-free pigment may be 

 present in the smooth muscle cells of the gastro-intestinal canal and of 

 the blood and lymph vessels, and in connective-tissue cells. This pig- 

 mentation is commonly associated with cirrhosis of the liver. Haemo- 

 chromatosis may be associated with diabetes mellitus and cirrhosis of the 

 liver, together with pigmentation of the skin "bronze skin." The con- 

 ditions leading to haemochromatosis are still obscure. 2 



HEPATOGENOUS PIGMENT. Pigmentation of tissues from the bile 

 occurs under various conditions. The bile may enter the blood and tis- 

 sue fluids in obstruction of the gall ducts by inflammation, tumors, cal- 

 culi, etc. In the condition called jaundice or icterus the tissues are 

 stained yellowish or yellowish -green by bile pigment. Icterus may also 

 occur in infectious diseases and in toxaemia, under conditions which lead 

 to destruction of red blood cells within the vessels. Bile pigment may 



1 To differentiate iron containing pigment in tissues, sections may be placed for an 

 hour in a mixture consisting of equal parts of a two-per cent solution of potassium fer- 

 rocyanide and two-per-cent solution of hydrochloric acid diluted with ninety-nine parts 

 of water. The iron-containing granules under these conditions become gree"n or bluish - 

 green. 



For a careful study of hajmochromatosis, with bibliography, see Opie, Jour. Exp. 

 Med., vol. iv., p. 279. 



