BLOOD-PLATES. 295 



On digesting the leucocytes with water, a. solution of a protein body 

 is obtained which can be precipitated by acetic acid and which forms the 

 chief mass of the leucocytes. This substance, which is undoubtedly 

 concerned in the coagulation of the blood, has been described under 

 different names, such as tissue fibrinogen (WOOLDRIDGE) cytoglobin and 

 praglobulin (A LEX. SCHMIDT) or nudeohistone (KossEL and LILIENFELD 1 ) 

 and consists ; chiefly at least, of nucleoprotein. The ordinary view that 

 this is nudeohistone does not seem to be correct, according to the recent 

 investigations of BANG, 2 and further proof is necessary. 



Besides these constituents of the protoplasm of the leucocytes we 

 must also include lecithin and especially phosphatides, cholesterin, glu- 

 cothionic, odd (in pus corpuscles, MANDEL and LEVENE S ) ; pu^ine bodies 

 derived from the nuclein substances and glycogen. According to HOPPE- 

 SEYLER glycogen is a constant constituent of all cells having amoeboid 

 movement, and he found it in the colorless blood-corpuscles but not in 

 the non-mobile pus-cells. Nevertheless glycogen has also been found 

 in pus-cells by SALOMON 4 and by others. The glycogen found by 

 HUPPERT, CZERNY, DASTRE, 5 and others in blood and lymph probably 

 originated from the leucocytes. Enzymes also occur in the leucocytes 

 and the proteolytic enzymes are of special importance. According to 

 OPIE and BARKER 6 two proteolytic enzymes occur in the leucocytes, 

 one of which is active in alkaline solution and occurs in the polynuclear 

 cells while the other is active in acid solution and occurs in the large 

 mononuclear cells. In regard to the other Constituents of the leucocytes 

 we refer to Chapter VII, on pus. 



The blood-plates (BIZZOZERO), hsematoblasts (HAYEM), whose nature, 

 preformed occurrence, and physiological importance have been much 

 questioned, are pale, colorless, gummy disks, round or somewhat oval in 

 shape, and generally with a diameter one-half or one-third that of the 

 blood-corpuscles. By 'the action of different reagents the blood-plates 

 are separated into two substances, one of which is homogeneous and non- 

 refractive, while the other is highly refractive and granular. Blood- 

 plates readily stick together and attach themselves to foreign bodies. 



1 See Wooldridge, Die Gerinnimg des Blutes (published by M. v. Frey, Leipzig, 1891); 

 A. Schmidt, Zur Blutlehre, Leipzig, 1892; Lilienfeld, Zeitschr. f. physiol. Chem., 18. 

 2 1. Bang, Studier over tfukleoproteider, Kristiania, 1902. 



3 Biochem. Zeitschr., 4. 



4 In regard to the literature on Glycogen see Chapter VIII. 



5 Huppert, Centralbl. f. Physiol., 6, 394; Czerny, Arch. f. exp. Path. u. Pharm., 31; 

 Dastre, Compt. rend., 120, and Arch, de Physiol. (5), 7. See also Hirschberg, Zeitschr. 

 f. klin. Med, 54. 



6 See Erben, Jochmann and E. Miiller, Jochmann and Lockemann, Hofmeister's 

 Beit rage, 11, which contains the literature. Opie, Journ. of exper. Medicine, 8; with 

 Barker, ibid., 9. 



