294 THE BLOOD. 



gravity than the red corpuscles, move in the circulating blood nearer to 

 the walls of the blood-vessels, and also have a slower motion. 



The number of white blood-corpuscles varies not only in the different 

 blood-vessels, but also under different physiological conditions. On 

 an average there is only 1 white corpuscle for 350-500 red corpuscles. 

 According to the investigations of ALEX. SCHMIDT 1 and his pupils, the 

 leucocytes are destroyed in great part on the discharge of the blood before 

 and during coagulation, so that discharged blood is much poorer in leu- 

 cocytes than the circulating blood. The correctness of this statement 

 has been denied by other investigators. 



From a histological standpoint we generally, as above indicated, dis- 

 criminate between the different kinds of colorless blood-corpuscles. 

 Chemically considered, however, there is no known essential difference 

 between them, and what little we do know chemically is chiefly in con- 

 nection with the leucocytes. With regard to their importance in the 

 coagulation of fibrin, ALEX. SCHMIDT and his pupils distinguish between 

 the leucocytes which are destroyed in the coagulation and those which 

 are not. The last mentioned give with alkalies or common-salt solutions 

 a slimy mass; the first do not show such behavior. 



The protoplasm of the leucocytes has during life amoeboid movements 

 which serve partly to make possible the wandering of the cells, and partly 

 to aid in the absorption of smaller grains or foreign bodies. On these 

 grounds the occurrence of myosin in them has been admitted even without 

 any special proof thereof. We know nothing with positiveness whether 

 in the leucocytes, or in the cells, in general, globulins occur with traces 

 of albumins, because cell constituents which used to be called globulins 

 have on more careful investigation been found to be nucleoalbumins 

 or nucleoproteins. The substance observed by HALLIBURTON, 2 and 

 occurring in all cells, which coagulates at 47 to 50 C., is considered as 

 a true globulin. ALEX. SCHMIDT claims to have found serglobulin in 

 equine-blood leucocytes which have been washed with ice-cold water. 



The proteins of the leucocytes as well as the cells in general are chiefly 

 compound proteins. For the present it is impossible to state to what 

 extent the nucleoalbumins occur in leucocytes or cells, because in the 

 past no careful differentiation was made between the nucleoalbumins 

 and nucleoproteins. The nucleoproteins are without any doubt the 

 chief constituents of the protoplasm of the white blood-corpuscles, and 

 one of these it seems is identical with the so-called hyaline substance of 

 ROVIDA, which yields a slimy mass when treated with alkalies or NaCl 

 solutions and which occur in pus-cells. 



1 Pfluger's Arch., 11 and Kriiger, Arch. f. exp. Path. u. Pharm., 51. 



2 See Halliburton, On the chem. Physiol. of the animal cell. King's College, London, 

 Physiol. Labor. Collected papers, 1893. 



