370 RETRoa RJ^KSJ 1 y; cii.w a eh 



still rcniains tlircc-foiutlis of the nucleic acid in an intact condition. Corper 

 publishes a scries of plates, toficther with the ciiemical details, thus establishing 

 a standard wliercby tlie histological changes can be interpreted in terms of tiie 

 chemical changes which cause them. 



It may be observed that autolysis of aseptically prosevved tissues 

 outside the body is much more rapid than is the autolysis of infarcts. 

 Mnd similar aseptic necrotic areas within the body. This may be due 

 to either or both of two factors : '^ First, autolysis is much slower in 

 alkaline than in acid media; outside the body autolyzing tissues de- 

 velop an acid reaction which favors their autolysis; within the body 

 this is checked by tlie plasma. Second, the ])'iasnia contains inhib- 

 iting substances, which also may interfere with self-digestion in the 

 body. In corroboration of the above may be recalled the fact that 

 large necrotic areas show autolysis first in the center, where the alka- 

 line, antagonistic body fluids presumably cause the least effect. Fur- 

 thermore, it has been found by Wells ^ that the histological changes 

 of autolysis proceed much faster in tissues placed in serum that has 

 been heated to destroy the antibodies than in unheated serum. Leuco- 

 cytes, as Opie has shown, contain autolytic enzymes acting best in an 

 alkaline medium, hence they perform their digestive function readily 

 at the periphery of necrotic areas, and coagulated tissue proteins, when 

 acted upon by body fluids, prodtice chemotactic substances whidi at- 

 tract leucocytes to dead areas."-' 



When a cell dies, certain physical changes occur that are probably 

 of considerable importance. The permeability of the cell wall is al- 

 most immediately increased, so that all diffusible substances readily 

 pass through, i. e., its semipermeable character is lost. This we see 

 particularly in plant cells, which lose their turgor with their semi- 

 permeability, and therefore the plant wilts. The cell structure is 

 also disintegrated, and as a result coordination of the cell chemistry 

 is at once destroyed.^" Intracellular enzymes escape into the blood 

 from areas of local death of cells,^"'' or as an agonal manifestation in 

 general death."*" Various dyes which cannot penetrate living cells 

 may stain dead or dying cells."^ These changes depend on alterations 

 ill permeability, and as permeability determines electrical resistance. 

 Osterhout has used the resistance of plant cells as an indicator of 

 vitality. He finds that normal cells have a rather constant resistance, 

 which is reduced by anything that lowers the vitality of the cell, and 

 in direct ])r()p()i'tion to the degree of injury or loss of vitality.^'"' The 



"Literature and more complete discussion under "Autolysis."' 



o.Tour. Med. Researcli, }<)()(] do), 149. 



naBiirger and Dold, Zoit. Tmmnnitiit.. 1014 (21), .378. 



10 See V. Prowazck. Biol. C-frM.. 1!)00 (29), 291. ri.ici suggests tli.it in 

 dead proteins, aldeliydes and amino •adicals iniite witli one anotlier to form cyclie 

 compounds (Arcli. sci. phys. nat., 191.') (40), ISl). 



i":i Maiidelbaum, ^liinch". med. Wooli., 1914 (Ol). 4()1. 



I'lhSchiillz, .Miinch. med. Woch., 191.3 ((10), 2.'')12. 



IOC Sec Steckelmacher, Beitr. path. Anat.. 101.3 (.-)7), 314. 



10(1 See Science, 1914 (40), 488. 



