THE GENERAL CONDITIONS OF LIFE 



325 



ing ; as a result of other transformations in the muscle the rigor 

 passes away, this process being accompanied by muscular relaxation. 

 A typical coagulation-necrosis in Weigert's sense occurs in muscle 

 under pathological conditions, especially in connection with fevers, 

 such as typhoid ; this is the so-called -waxy 'degeneration, which 

 consists in a coagulation of the muscle-substance with loss of 

 its cross-striation and a separation into waxy-appearing flakes 

 (Fig. 138). Similar coagulation-processes occur in other tissue- 

 cells, especially in active inflammations of the mucous membranes, 

 as in pharyngeal diphtheria. Finally, among the coagulation- 

 necroses in the wider sense there can be classed the pheno- 

 mena of cell-death that appear when, for the purpose of 



FIG. 139. Liquefaction at the edge of a blister caused by burning, a, Horny layer of the epi- 

 dermis ; b, rete Malpighii of the epidermis ; c, normal papilla; of the dermis ; d, cells swollen 

 and already partly liquefied ; e, partly normal cells ; /, liquefied mass ; g and h, swollen cells 

 with nuclei destroyed ; i, sunken papillae ; , coagulated exudation. (After Ziegler.) 



anatomical or histological preservation, living tissue is placed in 

 liquids that cause coagulation, such as mineral acids, alcohol, 

 sublimate, etc. These are the most acute cases of cell-death, and 

 for this reason these liquids are especially well-fitted for killing 

 and preserving. By their application the living cell is killed 

 suddenly ; it thus has not time to undergo extensive change, but 

 in a moment is fixed in a condition very similar to that of life. 

 In a third form of necrosis, liquefaction, the tissue-cells become 

 completely liquefied, their protoplasm disintegrating into a 

 granular detritus and the nuclei and cell-boundaries dissolv- 

 ing until the tissue is changed into a thickish liquid. Such 

 softenings occur especially in the formation of blisters after burn- 

 ing (Fig. 139), and frequently combine with coagulation-pheno- 



