Symptoms of A'ccrosis. 183 



lation of the chromatin in fragments or clumps of irregular size and 

 a variety of angular or globular shapes in the nuclear stroma along the 

 periphery (karyorrliexis), or its escape into the cytoplasm (pyknosis of 

 Schwann and Albrecht), or its complete dissolution (karyolysis of Klebs). 

 Besides this fragmentation of the nuclei, displacement and solution of their 

 chromatin, there are also to be observed changes in the cellular proto- 

 plasm and in the intercellular substance, resulting in the loss of specific 

 structure. The cell protoplasm and supporting tissue are changed into 

 a turbid, lumpy, more or less homogeneous mass, in which the individual 

 cells can no longer be recognized. In case lymph diffusion in the 

 necrosed tissue follows and coagulation occurs, the dead area seems to 

 be filled with apparently • swollen, shining, strongly refractile, fibrin-like 

 masses of transudate (fibrinoid of Albrecht and Schwann) of lumpy, 

 trabecular or reticulate appearance. In necrosis with softening the de- 

 structive change is usually recognized by the fat droplets (fatty detritus) ; 

 and the ichor of gangrenous parts shows, in addition to shreds of the 

 various tissues, the remnants of the liquefied red blood cells in the form 

 of yellow and dark brown granules and clumps of blood pigment, and 

 sometimes such solid decomposition products as leucin, tyrosin, margarin 

 and triple phosphates, together with an enormous number of putrefactive 

 microorganisms. 



Symptoms of necrosis. Local death of tissues causes their com- 

 plete loss of functional ability. \Mien the necrosed focus is of 

 small size and situated in the midst of healthy functionating tissue 

 of the same type and having the same character of activities, 

 there are often no symptoms, as in case of anaemic infarcts of the 

 kidney and spleen. The distribution and production of heat ceases 

 in the necrosed part with the cessation of the blood supply ; gross 

 areas of gangrene on the periphery of the body, as the skin, ears 

 or extremities, feeling cold. Because of the coincident death of 

 the sensory nerves within the gangrenous area the latter is itself 

 'analgesic, although the inflammatory reaction at the periphery 

 causes sensations of pain. Gangrene in its inception is further 

 recognizable in parts of the body exposed to view by the dark 

 brown, dirty dark red to dark green discoloration, by the desic- 

 cation, or by its putrid odor. In this latter form, that is, gangrene, 

 the parts assume a doughy, flabby consistence; and if the gases 

 cannot easily escape and accumulate deep in the meshes of the 

 tissue there may be felt by light palpation a crackling {crepitation) 

 of the breaking or displaced gas bubbles. The presence of the 

 gases gives the putrefying tissue a bloated, spongy appearance, the 

 cut surface full of small holes (gangrenous emphysema) ; together 

 with the ichorous fluid these gases often accumulate under the 

 epidermis in cutaneous gangrene and cause the formation of gan- 

 grenous blebs. 



