412 BLOOD AND LYMPH. 



found in the serum than in the plasma. This fact is explained by 

 supposing that during coagulation some of the leucocytes disinte- 

 grate and part of their substance passes into solution as a globulin 

 identical with or closely resembling paraglobulin. Paraglobulin as 

 obtained from blood-serum by half saturation with ammonium 

 sulphate or full saturation with magnesium sulphate does not behave 

 like a chemical individual. Portions of it, for instance, are precipi- 

 tated by CO 2 or by dialysis, and portions are not so precipitated. 

 Recently, therefore, it has been 'assumed that paraglobulin is in 

 reality a mixture of two or possibly three different, although re- 

 lated, proteids. The separation usually given is into euglobulin 

 and pseudoglobulin, euglobulin being the portion precipitated by 

 ammonium sulphate when added to one-third saturation (28 to 33 

 per cent.), and pseudoglobulin the portion precipitated only by 

 one-half saturation (34 to 50 per cent.). The latter portion shows 

 properties more nearly related to the albumins.* The whole basis 

 of classification is, however, unsatisfactory and provisional (see 

 appendix). It is even stated that under certain conditions of 

 temperature and reaction serum-albumin may be converted to a 

 globulin body that precipitates upon one-half saturation with 

 ammonium sulpha te.f The origin of paraglobulin remains unde- 

 termined. It may arise from the digested proteids absorbed from 

 the alimentary canal, but there is no evidence to support such a 

 view. Another suggestion is that it comes from the disintegration 

 of the leucocytes (and other formed elements) of the blood. These 

 bodies are known to contain a small quantity of a globulin resem- 

 bling paraglobulin, and it is possible that this globulin may be liber- 

 ated after the dissolution of the leucocytes in the plasma, and thus go 

 to make up the normal supply of paraglobulin. Several observers^ 

 have claimed that during starvation the proportion of globulins 

 in the blood is increased relatively or absolutely. A possible 

 explanation is that the increase is due to cell globulins received from 

 the tissues which must undergo destruction and dissolution in pro- 

 longed fasting. The fact remains, however, that our knowledge is 

 too incomplete at present to venture any positive statements 

 regarding the origin and specific functions of the paraglobulin. 



Fibrinogen is a proteid belonging to the globulin class and exhibit- 

 ing all the general reactions of this group. It is distinguished from 

 paraglobulin by a number of special reactions; for example, its 

 temperature of heat coagulation is much lower (56 to 60 C), and 



* Porges and Spiro, "Beitrage zur chem. Physiol, u. Pathol.," 3, 277, 

 1903; and Freund and Joachim, "Zeitschrift f. physiologische Chemie," 36, 

 407, 1902. 



t Moll, " Beitrage zur chem. Physiol, u. Pathol. " 4, 561, 1903. 



% See St. Githens, "Beitrage zur chem. Physiol, u. Pathol.," 5, 515, 1904; 

 also Lewinski, "Pfliiger's Archiv f. d. gesammte Physiol.," 100, 611, 1903. 



