THE NITROGEN COMPOUNDS 55 



quite generally distributed in the seeds of agricultural 

 plants, having been found in a larger number than 

 any other protein yet discovered, including all the 

 cereals, castor bean, cottonseed, flaxseed, hemp, squash, 

 and sunflower, although it is not abundant in any of 

 these. 



69. Animal globulins. — ^The animal globulins exist 

 abundantly in muscle and blood. If finely divided, well- 

 washed muscle (lean meat) is treated with a 10 per 

 cent salt solution, first by rubbing it in a mortar with 

 fine salt, and then adding enough water to secure the 

 proper strength of solution, a globulin is dissolved which is 

 derived from a muscle protein designated by some authors 

 as myosin. It is believed that myosin coagulates in the 

 muscle upon the death of an animal forming a clot some- 

 times called myosin-fibrin. The theory has been proposed 

 that myosin acts as a "mother" substance in the muscle 

 from which myosin-fibrin is formed in much the same 

 way as fibrin is developed in clotting blood from a pre- 

 existing body, but no single view as to exactly what 

 occiu-s is fully accepted. Other terminology has been 

 proposed, viz., that the mother substance shall be named 

 myosinogen to correspond to fibrinogen, myosin being the 

 coagulation product. Much confusion and indefiniteness 

 exist with reference to the chemistry of muscle proteins. 

 There is, nevertheless, a general agreement that rigor 

 mortis is due to a clotting of the muscle, accompanied by 

 marked chemical transformations. It is held that fer- 

 ments are present in the muscle, to the influence of which 

 these changes are due, and without which they do not 

 occur. 



Another prominent globulin is the fibrinogen found in 

 the blood. When blood is drawn from the veins and cools, 



