56 PROTOPLASMIC ACTION AND NERVOUS ACTION 



structures, such as the nuclear and plasma membranes.^ 

 It is interesting to note that a visible alteration or 

 breakdown of protoplasmic structure seems always to 

 be associated with the death process, however induced; 

 even after natural death, coagulative or other alterations 

 occur in most forms of protoplasm; death rigor, increased 

 permeability, and loss of tensile strength in muscle cells, 

 are examples of such effects. The death change involves 

 a structural disintegration, with which is associated a 

 loss of normal chemical activity. 



A second class of cases, in which certain chemical 

 reactions may be promoted instead of hindered by the 

 breakdown of normal cell structure, also throws light 

 upon the relation of structure to the chemical activity 

 of protoplasm; an example is the autolytic breakdown of 

 proteins or of glycogen in dead liver cells or other 

 autolyzing cells. The rate of such breakdown is 

 increased when the structure is altered by death, and 

 still more so (according to Chiari's observations) in 

 the presence of lipoid-solvent compounds like chloroform.^ 

 Such facts illustrate another form of chemical control 

 exercised by protoplasmic structure. Apparently they 

 indicate that a partitioned or alveolar structure exists 

 during life; enz}Tiie and substrate, for example, may thus 

 be kept apart while this structure is intact, but on death 

 the interalveolar partitions are broken down and inter- 

 action results. It has been suggested by Hofmeister^ 

 that this chambered type of architecture is what renders 

 it possible for a variety of chemical reactions to occur 



* R. S. Lillie, Journal of Biological Chemistry, XV (1913), 237. 

 ^ Chiari, Arch, exper. Path. Pharmakol., LX (1909), 256. 

 3 Hofmeister, lac. cit. 



