240 THE ADRENAL SYSTEM AND VASOMOTOR FUNCTIONS. 



conception of the nature of blood-plasma as an excipient for 

 an oxidizing agent of adreno-pulmonary origin, on the one 

 side, and, on the other, recall the view of Englemann, that a 

 fluid substance passes from the bright bands of the fiber 

 i.e., the interstitial disks into the dark bands i.e., the con- 

 tractile disks, the intimate process would be as follows: The 

 hydrocarbon compounds would occupy the contractile disks, while 

 the oxidizing substance would fill the interstitial disks, and on the 

 proportion of the latter entering the contractile disks would depend 

 the activity of the oxidation process. 



Further evidence that the general process outlined pre- 

 vails may be obtained by tracing the identity of myosin: the 

 substance found in the muscles after death. "While dead 

 muscle contains myosin, albumin and other proteids, extractives, 

 and certain insoluble matters, together with gelatinous and 

 other substances not referable to the muscle-substance itself," 

 says Professor Foster, "living muscle contains no myosin* but 

 some substance or substances which bear somewhat the same 

 relation to myosin that the antecedents of fibrin do to fibrin, 

 and which give rise to myosin upon the death of the muscle. 

 There are, indeed, reasons for thinking that the myosin arises 

 from the conversion of a previously existing body which may 

 be called myosinogen, and that the conversion takes place, or 

 may take place, by the action of a special ferment, the con- 

 version of myosinogen into myosin being very analogous to 

 the conversion of fibrinogen into fibrin. We may, in fact, 

 speak of rigor mortis as characterized by a coagulation of the 

 muscle-plasma comparable to the coagulation of blood-plasma, 

 but differing from it inasmuch as the product is not fibrin, 

 but myosin. The rigidity, the loss of suppleness, and the 

 diminished translucency appear to be, at all events, largely, 

 though probably not wholly, due to the change from the fluid 

 plasma to the solid myosin. We might compare a living muscle 

 to a number of fine transparent membranous tubes containing 

 blood-plasma. When this blood-plasma entered into the 'jelly' 

 stage of coagulation, the system of tubes would present many 

 of the phenomena of rigor mortis. They would lose much of 



* All italics are our own. 



