DIFFUSE CASSATION. 269 



be noticed large multi -nucleated cells, the nuclei of which 

 are arranged about the periphery of the cell or grouped 

 irregularly at its poles. The arrangement of these 

 nuclei appears in the sections sometimes as oval, some- 

 times as somewhat crescentic in its grouping. In the 

 tubercles from the human subject these large " giant- 

 eel Is," as they are called, are quite common. They are 

 much less frequent in the tubercular tissues from lower 

 animals. 



Round about this central focus of necrosis is seen a 

 more or less broad zone of closely packed small round 

 and oval bodies which stain readily but not homogene- 

 ously. They vary in size and shape, and are seen to be 

 imbedded in a delicate network of fibrinous-looking 

 tissue. 



This fibrin-like network in which these bodies lie, 

 and which is a common accompaniment of giant-cell for- 

 mation, is in part composed of fibrin, but is in the main, 

 most probably, the remains of the interstitial fibrous 

 tissue of the part. This zone of which we are speaking 

 is the zone of so-called " granulation tissue/' and con- 

 sists of leucocytes, granulation cells, fibrin, and the 

 fibrous remains of the organ ; the irregularly oval, 

 granular bodies which take up the staining are the 

 nuclei of these cells. The zone of granulation tissue 

 surrounds the whole of the tubercular process, and at 

 its periphery fades gradually into the healthy surround- 

 ing tissues or fuses with a similar zone surrounding 

 another tubercular focus. This may be taken as a 

 description of the typical miliary tubercle. 



DIFFUSE CASSATION. The diffuse caseation, as said, 

 plays a more important role in the tuberculous lesion, 

 both in the human and experimental forms, than does 



