EXTRACTIVE BODIES OF THE MUSCLES 545 



Myoproteid is a protein found by v. FURTH in the plasma from fish- 

 muscles. It does not coagulate on boiling, is precipitated by acetic 

 acid, and is considered as a compound protein by v. FURTH. 



In connection with v. FURTH 's work, PRZIBRAM has carried on investiga- 

 tions on the occurrence of muscle-proteins in various classes of animals. The 

 myosin (v. FURTH) and myogen occur in all classes of vertebrates; the myogen 

 is always absent in the invertebrates. Myoproteid occurs, at least in considerable 

 quantity, only in fishes. In the muscle after cutting the nerve, STEYRER J found 

 somewhat more musculin and less myogen in the muscle-juice than in the normal 

 muscle. 



Muscle-pigments. There is no question that the red color of the 

 muscles, even when completely freed from blood, depends in part on 

 haemoglobin. K. MORNER has shown that muscle-haemoglobin is not 

 quite identical with blood-haemoglobin . The statement of MACMUNN 

 that in the muscles another pigment occurs which is allied to hsemo- 

 chromogen, and called myohcematin by him, has not been substantiated, 

 at least for muscles of higher animals (LEVY and MORNER 2 ) . MACMUNN 

 claims that myohaematin occurs in the muscles of insects, which do not 

 contain any haemoglobin. The reddish-yellow coloring-matter of the 

 muscles of the salmon has been little studied. 



Various enzymes have been found in the muscles. To these belong 

 (besides traces of fibrin ferment and myosin ferment) the catalases and 

 oxidases, which occur only to a slight extent. The disputed glycolytic 

 enzyme (Chapter VIII), whose nature is unknown, probably belongs to 

 the oxidases. An amylolytic and a proteolytic enzyme (HEDIN and 

 ROWLAND 3 ) have also been found, and the hydrolytic and oxidizing 

 enzymes (Chapter XV) active in the formation and destruction of uric 

 acid are also present. 



Extractive Bodies of the Muscles. 



The nitrogenous extractives consist chiefly of creatine, on an average 

 of 1-5 p. m. in the fresh muscles containing water, also the purine bases, 

 hypoxanthine and xanthine, besides guanine and carnine, but chiefly 

 hypoxanthine. The purine bases probably do not occur as such, but as 

 complex combinations. The quantity of nitrogen as purine bases amounts, 

 according to BURIAN and HALL, in the fresh flesh of the horse, ox, and calf 

 to 0.55, 0.63, and 0.71 p. m. respectively, or 1.3-1.7 p. m. calculated as 



1 Przibram, Hofmeister's Beitrage, 2; Steyrer, ibid., 4. 



2 See MacMunn Phil. Trans, of Roy. Soc., 177, part 1, Journ. of Physiol., 8, and 

 Zeitschr. f. physiol. Chem., 13; Levy, ibid., 13; K. Morner, Nord. Med. Archiv, Fest- 

 band, 1897, and Maly's Jahresber., 27. 



3 Zeitschr. f. physiol. Chem., 32. 



